Are Small Boats Seaworthy?

 

“A small boat, properly designed, is safer than a bigger one. Bigger boats create bigger and more dangerous forces. They also demand complicated technology. Complicated technology in the marine environment is vulnerable. Only in a small functional boat do you have absolute control. Only in a small boat are you safe in the ruthless fury of storms.”

Sven Yrvind

 

It’s commonly accepted that very big boats are much safer out at sea than very small ones. Are they really? Many people have gone out to sea in small boats and survived, often thoroughly enjoying the experience.

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Mast Height and Sailing Under Bridges

I’ve preoccupied myself with having a mast that can be lowered underway to pass under a bridge, but I forgot how small my dream boat has become. Consequently it will only need a small sail, and will be safer under-canvassed anyway. Such a short mast will be easy to handle.

It might be so short that there’s no need to handle it at all whilst underway. Look at this photo of Alistair Law’s Paradox Little Jim on the River Thames:

Little Jim casting off just below a lock on the river - the mast is up and it looks like it passed straight under a bridge with no problems.

It appears that the whole flotilla has passed under the bridge without a problem (it’s the UK Home Boat Builder’s Rally by the way). I’m particularly interested in passing easily under the bridges of the River Thames because those are my home waters and there are about seventy bridges between Oxford and London.

Thankfully the Environment Agency have been most helpful and published the height of every bridge from Lechlade to London, to see them click here. Then the heights of all the bridges on the tidal Thames have been published by the Port of London Authority, click here. They list the clearance below every arch of every bridge, all the way through London and out to sea at various states of the tide.

From what I’ve read Paradox‘ mast is about twelve feet high, and I would estimate the design has about two feet of freeboard, so the mast might be about fourteen foot off the water’s surface. Looking at the bridge height tables, Paradox should be able to sail all the way from the sea up the Thames past Windsor Castle to Cookham Lock Cut Bridge between Maidenhead and Marlow, which has a maximum clearance of 12’6″. After that another five bridges before Oxford would also be too low.

Of course some of the ones I’ve skipped are only just high enough so great care should be taken to aim for the middle of the highest arch. Perhaps the boat could be careened to pass under bridges as low as ten foot, I do not know.

Even lower? Sven Yrvind’s latest creation Yrvind.com has a ten foot fore mast, giving a total air draft of about twelve feet:

Yrvind.com on a close haul in the Stockholm archipelago. The boat is bright yellow and blue after the Swedish flag.

This boat could sail up the Thames from the sea as far as Folly Bridge in Oxford without taking the mast down. That would be ideal for me because I want to sail on the coast but also up the river to see my parents who live in Oxford.

Interestingly Yrvind has no interest in bridges because his passion is the open ocean. He rigs as a yawl with a very low aspect ratio for seaworthiness, to keep the centre of effort low and ensure the rig is easy to handle in a storm.

How Low?

Of course there’s no limit to how low the bridges get – a boat this small could navigate the charming River Cherwell in Oxford which has a bridge with a clearance of about five feet. The lowest bridge on the Thames is also in Oxford – Osney bridge has a clearance of 7’6″:

Low Victorian blue iron bridge labelled with a sign: DANGER LOW BRIDGE

A five foot mast could sail under Osney Bridge but not very fast! Although too short for the main sailing rig of a small cruiser, it might be an interesting idea for a second rig. For example Yrvind.com has two rigs, one of them is a shorter mast for heavy weather. A very short second rig could have interesting multi-purpose: at sea for storm sails, and jury rigging after a dismasting; inland on the river for breezy days to sail straight under low bridges and over-hanging trees.

Realistically I think I should aim for a mast height like Yrvind’s – ten foot – low enough to get from the sea through London all the way up to Oxford without lowering the mast. The lowest bridge will be 12’6″.

A Mast That Lowers Easily

This is still desirable for many navigations in this country, especially the canals. Some useful data about size restrictions for the canals of the UK can be found here. There are many bridges around the seven foot mark, and the lowest on the Trent & Mersey canal has a 5’9″ air draft. Of course these are not listed for mast height, rather for barges with standing headroom so that they don’t end up crashing to become like an open-top bus.

Sailing the canals would not be practical if the mast wasn’t designed to lower underway. A Paradox would be forced to stow the whole rig and continue under yuloh power. After all, Matt Layden wasn’t anywhere near these canals, he designed it for the east coast of the USA.

Scenic low bridge surrounded by greenery

Why Sail on the River?

Good point. On the upper reaches of UK rivers, in the lowest point of the valley there are lots of trees and not much wind. But I have noticed some days with a fair breeze, and many more with a waft of wind enough to make progress. On days with a decent breeze it would feel silly not to be able to make the most of it. And when it’s windy trying to maintain control when sculling along with a yuloh could be quite challenging. I’d rather be enjoying sailing on a beam reach than being pushed into the bank. Wind may be more of an issue on exposed stretches of canal.

I’ve lived along the River Thames for fifteen years and not once have I ever seen a boat sailing on a voyage along the river, not even in London. There are some dinghy sailing clubs but they tend to tack around on a short stretch of the river in between two bridges or locks.

It was not always so. Before the motor car, before the railways, when there were very few bridges and the waterways were the most efficient way to transport bulk cargo, the upper Thames was adorned with all kinds of wooden craft and sails of different shapes and sizes. Just imagine the peace and quiet and birdsong.

a painting of two large sprit-sail barges sailing up the upper Thames a long time ago

Now it’s adorned with big white plastic petrol-powered cruisers. Wouldn’t it be something quite special to see a sail gliding above the banks again, completely ignorant of the bustle of modern life. Now there are seventy bridges in the way, but with a small enough rig…

No to the Mast-Aft Rig

The A-frame aft mast was just an idea I had for a mast that could be lowered forward until flush with the deck, the coachroof passing through the gap in the double-mast. This would give a real minimal air draft when lowered, and put it all out of the way completely when under human power.

Taking a look at Bill Serjeant’s Paradox Faith sailing on a close reach it’s quite obvious that my idea for an A-frame aft mast is not possible on a boat of this length with the chine runner concept:

The balanced lugsail rig in action.

The chine runner concept enables a boat to sail to windward without the need for a deep keel or foils by making use of the hard-chined shape of the hull and an over-sized rudder. This places the centre of lateral resistance further aft than in a conventional sailing boat. Accordingly the centre of effort must also be further aft to balance the rig, otherwise you get lee helm.

Looking at photos of Paradox sailing upwind it’s evident that to get the centre of effort of an aft-mast rig in the right place, and get some forward rake on the mast, the foot of the mast must be almost on the transom. To keep the forestay tight, the backstay must be several feet aft of the foot of the mast, I would guess at least six feet, which is six feet behind the boat!

It might work with a long sprit aft of the transom, but this would put the stern under immense stress. Perhaps with a much longer boat over twenty foot there might be enough length for the backstay without using a stern sprit, but only if the boat is seriously under-canvassed.

I think I’ll leave the experiment to designers of more conventional keel-boats that have a big bow dagger board and a centre of lateral resistance much further forward. No mast-aft for me.

A catamaran with a mast near the stern, raked towards the bow, and a single large foresail

Minimalist Boat

In my last discussion I established that I must temporarily ignore all the boats I’ve ever seen in order to work out what kind of boat is ideal for me, starting from first principles. I must also temporarily wipe away my previous design ideas like having a cockpit at the stern, and start from square one. Once I’ve established the smallest, most simple boat that I need, I can then consider whether it’s worth adding to its size or complication to add further luxury, convenience or functionality. Finally I can reopen my eyes to all the boats around me in the hope that one of them is similar to my ideal boat.

I think I’m becoming a minimalist – I just can’t stand having anything that I don’t need, and that includes material things as well as responsibilities. More stuff, more things to go wrong, more expense, more stress. I’m down to a bicycle and one bag now, that’s all I need in this world – in fact I don’t even need the bike but it’s just fun to have.

It’s only natural that I take the same approach to boating. The first question is of course whether I need a boat in the first place, but that’s covered in my boat page where I conclude that I don’t need a boat, I just want one. I want to live on the water, enjoying the sights and sounds from its surface, the freedom, comfort, security and independence afforded by a floating mobile home. So given these criteria, what’s the smallest and most simple boat I can live and cruise on?

Going back to first principles, this is about how to live and move on water. Like most humans I float, but in most waters on this planet if my body’s submerged for long enough I’ll die of hypothermia, thirst, starvation, sleep deprivation, getting stung or eaten. So what can protect me from these evils?

Without being too pedantic, I need to live in the atmosphere not in the water, and a submarine is far too complicated so I’ll start with a raft. In ancient times whole communities voyaged across the Pacific on rafts, so it’s not a ridiculous proposition. On the other hand I also want to cruise the much colder waters around Britain. The only way to stay warm and dry in every weather condition would be to wear a dry suit and lots of insulation, which I don’t want to wear 24 hours a day besides the fact that it won’t protect my hands and face from the icy spray. Furthermore I won’t be able to indulge in some pleasant reading or surf the Internet when the weather deteriorates.

A painting of a balsa raft with some people, sails and shelters on top

So I quickly move on to a boat with a waterproof, insulated cabin. The insulation not only adds warmth but prevents condensation making the cabin even drier. One great advantage of a waterproof cabin is that it adds a lot of buoyancy high above the bottom of the boat, so that, depending on the shape of the rest of the boat, it will not be so stable upside-down but more likely to turn the right way up again. A big enough cabin would also enable me to lie down, taking care of sleep deprivation, store food and water, and protect me from sharks and Portuguese man o’ war.

It makes sense to have a long thin boat for two reasons – that’s the shape of my body when I’m lying down, and the boat will have much more directional stability than a sphere or a cube. Directional stability is essential if I want to move the boat efficiently under oar or sail.

The third dimension is about how much headroom I need. I need one foot to lie down, three feet to sit on the floor, four feet to sit on a chair, just over six feet to stand up and nearly eight feet for a full morning stretch.

I can do all these things outside my boat on terra firma. I’m homeless and boatless now and I have no problem, I’m always comfortable. So the important question is how much time will I spend inside my boat away from land? The answer is not much – I anticipate 0% for the first couple of years living aboard, rising to 1% after many years of experience. The other 99% will be spent cruising by the coast, up a river or along a canal, where I can alight any time I feel like stretching my legs. Many sailors will tell you: “Three quarters of our planet is water, but the most interesting part of the water is next to the land.” I would also like to suggest that the most interesting part of the land is next to the water.

So how much time will I spend inside my cabin? Well it’s the first place I’ll head in cold or wet weather. I’m most likely to experience this kind of weather here in Northern Europe and in other first world countries, where I can also hide from the elements at work, in public libraries or café’s, not to mention visiting friends. I conclude that I don’t need to stand up in my cabin but I do need to lie down full stretch, and it would be nice to be able to sit and read at least on the floor. I can’t imagine being forced to lie down for a whole day of stormy weather.

That means I need a cabin interior at least 6’2″ long, 3′ high and 2′ wide (to accommodate my shoulders). Interestingly all the minimalist boat designers that I mentioned in my last post – James Wharram, Matt Layden, and Sven Yrvind – came to the same conclusion about headroom, that they wanted just enough to be able to sit on the floor. Here’s a picture of Sven Yrvind sitting on the floor in his latest boat:

Sitting on the floor, hair brushing the roof

Why is headroom such an issue? The higher the boat rises from the water’s surface, the more likely it is to be blown around in the wind, not usually in the direction one would like to travel. Big powerboats overcome these forces by using the vast amount of energy stored in fossil fuels to power an engine. I don’t want an engine, for practical and environmental reasons – neither did these other boat designers. But we all want to be able to sit and read in the cabin so three feet is the compromise.

Of course there are certain daily activities that would benefit from more headroom, like bathing or sitting on the toilet, but as these things can be done outside the boat I’ll leave them out for now. Again, I’ve been homeless and boatless for a year and have had no problems.

Now I don’t need the whole cabin to be high enough to sit in, only where my head and shoulders would be. And when sitting I don’t need such a long cabin. It recently struck me that in the smallest possible boat I would lie on top of my storage, giving only two feet of headroom, then when I want to sit up I can move some of the storage towards the ends of the boat, giving three feet of headroom where I sit. It’d be like having a traditional cabin sole but leaving a large well to sit in.

Encouraged, I drew cross sections of this hypothetical smallest boat on squared paper, on a scale of five little squares to one foot. I shaded in the area that represented my body, and put dots in potential storage areas:

My pencil drawing on squared paper of the smallest possible boat that I could lie and sit in comfortably - cross-sectional view, two foot beam

I quickly realised that a boat with only a two foot beam might be more stable on it’s side, and I don’t want to have to right the boat every time I want to sit up. I increased the beam to three feet to give it more initial stability and righting arm when heeled:

My pencil drawing on squared paper of the smallest possible boat that I could lie and sit in comfortably - cross-sectional view, three foot beam

Next to a profile and plan view I made displacement estimates based on a draft of 6″, 9″, and 12″.

My pencil drawing on squared paper of the smallest possible boat that I could lie and sit in comfortably - plan view, three foot beam

I estimate that a heavily insulated hull would be about three inches to add to the outside dimensions on each side. I only need the maximum beam at my shoulders so the shape tapers. I’m not sure whether I really need a pointy bow so I’ve left it plumb for now in keeping with the minimalist approach.

Why the flat, rockered bottom? This is for the chine runner concept to work. I don’t fully understand it and will also have to carefully consider the waterline length, beam, and size of rudder later on in the design process. Why do I need the chine runner concept?

I went over this in a previous article but essentially it’s the most simple way for a small boat to resist leeway when sailing in shallow water which is one of the design criteria:

  • Shallow enough to explore canals and rivers
  • Seaworthy enough to cross an ocean
  • No engine
  • A sail with a mast that drops to go under low bridges
  • Small and light enough to portage over land without employing an engine
  • Carbon neutral for cooking, heating and computing energy

Conveniently such a small nutshell of a boat ticks off all of these criteria! The low wetted surface area and light weight make it easy to propel with human power over land and water of any depth, no engine required. Very little energy is required to heat the cabin – in fact my body heat is enough. Having such a shallow draft and high centre of gravity the mast must be short, which means it’ll be easy to lower and lash on deck, and won’t generate too much force so can be stepped on deck leaving the small cabin space free. And best of all being small makes the boat much more seaworthy.

The remaining question is how much will it weigh? In typical British fashion I shall now mix in some metric units. I weigh nearly 100 kg. At six inches draft the above boat will displace something in the region of 170 kg water, at nine inches more like 250 kg. So even at nine inches I only get 150 kg left over for the weight of my boat including rigging, my supplies and anything else I want to bring along. If I want a more pointed bow for wave piercing at the same length I get even less displacement.

Of course I might want a bit more displacement than this, but my point is that this is the right place to start, from first principles – a waterproof, insulated cabin with just enough space for me to sit down and lie down.

This is plenty of space for me. Sound ridiculous? I disagree, it’s just a completely different way of thinking about the inside of a boat. What’s the point in being able to turn around or stand up when there’s nowhere to walk to, and everything is at arm’s reach? I can stand up outside the boat on the beach or the riverbank.

Now that I’ve established the bare minimum, it’s time to think about how much more displacement I need, and how much more space for anything else I consider essential. For example, do I want to be able to carry a folding bike? Or a girlfriend, or a guitar? After all, these are the important things in life.

I Question Everything including Boat Design

I used to assume that everyone around me was living in the best way possible – that society had developed rapidly over the last few hundred years thanks to the diligence of scientists and engineers so I should live as they do and not try to reinvent the wheel. However this last year has made me think very differently.

I still do most things just like everyone else, but it seems that often when I question something major I turn out to be right. I don’t want to become an arrogant hermit, but this does give me courage to question even more.

All of my friends and family had a motor car – I questioned whether that was necessary and discovered I’m much better off on a bicycle.

I questioned why I was taught to use ten litres of clean drinking water to flush a bit of urine down the toilet even when there’s a drought. I discovered if I go outside behind the bushes nobody cares and I put valuable water and nitrogen back into the soil.

A year ago I questioned whether I really need to have a centrally heated building with electricity and running water. I’ve been happy and homeless for over a year now and have no intention of going back.

My little green tent in the copse at the top of Wittenham Clumps, Oxfordshire

Being nearly thirty I’m now feeling peer pressure from friends and relatives to find a wife and have kids because I’m the eldest, my parents have just turned sixty and they’re itching for grandchildren. Of course I love spending time with girls, but to dedicate twenty years to bringing up kids? I’m perfectly content living on my own so why should I go to all that stress and expense to double my carbon footprint and add to the 7,009,284,363 people on this planet?

I also question why we have to buy meat from the supermarket that has been reared in captivity somewhere far away, consumed fossil fuels to be transported and refrigerated, when there are loads of ducks and rabbits running all around us that are perfectly edible. They’re wild and free, and no doubt when I get around to cooking them I’ll discover that they taste just as good.

Still, I approached the world of boating with an open mind, assuming that they all knew better than me. It takes many years to develop an experienced sailor, boat designer or builder, so I should be quiet and listen. There were many varying opinions, but the mainstream consensus was the following:

  • It’s not practical to live on a boat that doesn’t have standing headroom.
  • It’s not practical to live on a boat that doesn’t have an engine.
  • It’s impossible to live on a boat that you can move around easily with your own muscle power.
  • To go out to sea safely you need a really big boat, with a deep keel and deep, heavy ballast.
  • An amateur with absolutely no experience should never attempt to design a boat to live on.
  • Foam-core composite construction is not for amateurs.

But being the stubborn annoying type that I am, I kept digging, determined to get the kind of boat I wanted, because I wanted it so much. I really wanted to live on a boat with the following criteria:

  • Shallow enough to explore canals and shallow rivers
  • Seaworthy enough to cross an ocean
  • No engine
  • A sail with a mast that drops to go under low bridges
  • Small and light enough to portage over land without employing an engine
  • Carbon neutral for cooking, heating and computing energy

I just couldn’t take no for an answer. It’s rather embarrassing for me to read now, but I must include links to the threads on the Wooden Boat Forum and the Cruisers Forum where as a complete novice I discussed this kind of boat. In digging a little deeper, I discovered that luckily for me, there are some respected members of the boating community who have already questioned these things. When they did, they usually met with disbelief and ridicule.

In 1954 when Englishman James Wharram built his first catamaran to sail across the Atlantic it was one of the first ever in the western world, drawing only a few inches. People told him he was building two coffins to bury himself at sea – they said: “They will never make it. Five hundred miles to North Spain across the Bay of Biscay. I know those waters. They will die.” He said: “I had my own ideas and paid no attention.” And sure enough, here we see that same catamaran, Tangaroa, at anchor in Trinidad having successfully sailed across the Atlantic:

Tangaroa - a 23ft 6in x 11 ft plywood catamaran

When someone said the trade winds were too easy, he built another catamaran in Trinidad and sailed it with his two girlfriends back to Britain across the North Atlantic, proving catamarans seaworthy and starting a world revolution in boat design.

Wharram also questioned how much living space you need to live and voyage on a boat. Inside her cabins Tangaroa had only 2′ 6″ beam and 3’10″ headroom, where they could “sit up cross-legged or half lie over an area the size of an average single bed”. He writes:

With my adventurous life behind me, this boat seemed like luxury, though other people described it as “two coffins tied together”, or “living in a wardrobe pushed on its side”.

I don’t know about his adventurous life except that he had lived and worked on numerous boats, and enjoyed hiking in the Lake District so I assume he was experienced in the simple outdoors life and living in tight quarters. I hope that my current lifestyle of homelessness will also qualify me to live in a small boat.

In the 1980′s the American Matt Layden challenged the belief that sailing monohulls need deep foils like centreboards or leeboards to resist leeway, when he discovered how to use the whole hull as a foil and invented the chine runner concept. He also questioned whether you need a big engine and standing headroom to live on a boat.

After ten years living and cruising in different designs his conclusion was the famous Paradox. It has little over three feet of headroom, a beam of four feet, a draft of only nine inches and a single sculling oar called a yuloh instead of an engine. As far as I’m aware the only reason he moved out of the boat was to start a family.

Matt Layden sailing the first Paradox on a broad reach

There have been many pioneers who have achieved the ‘impossible’ out on the seas in unconventional craft. But I’ll conclude with the Swedish designer/builder/sailor Sven Yrvind who questioned the idea that small boats are not seaworthy.

In 1968 after sailing a fourteen foot skiff from Sweden to the Isle of Wight, yachtsmen convinced him that a big boat would be more seaworthy, comfortable and go much faster. So he rebuilt a forty foot wreck and sailed it from Sweden to Rio de Janeiro, only to conclude:

A bigger boat doesn’t make you happier, but it costs more not only to build but also in upkeep. It is also more difficult to manoeuvre and find a place for in harbour. It sure has many advantages like speed and carrying capacity and prestige but they did not mean much for me, so weighing it all together as one has to do I understood that my values and my heart favoured the small one.

So in 1971 he cold-moulded a twenty footer called Bris in his mother’s cellar. Despite people saying he’d never get the boat out of the door, he sailed her from Norway to Iceland against gale force winds then right down to Patagonia. Trying to round Cape Horn against the prevailing winds his boat did a 360° flip then a somersault while he was inside with his girlfriend, casually reading a 778 page book on physics and philosophy. He says:

The weather was heavy; but not in the way I had imagined. Apart from that the boat capsized and pitch-poled now and then I did not complain. The storms were edifying. They complemented my theoretical knowledge. They gave me personal experiences. I got new ideas. I prudently drew a new boat and decided to make a new try.

You can read the full story on his website at yrvind.com/my_life. Here’s a video of Bris:

He continued to design and build small ocean-going boats and test them in rough seas for the rest of his life. They got smaller and smaller – last year he sailed a fifteen footer from Ireland to the Caribbean and this year, aged 73, he’s building a ten foot boat in which he will sail around the world in the Southern Ocean.

Just like Wharram and Layden, Yrvind was perfectly happy with three feet of headroom inside his boat and he didn’t need an engine. Here he is pictured inside Bris’ cabin – he’s a short fellow so my guess is there’s even less than three feet:

Yrvind sitting on the cabin sole inside Bris. His hair brushes the coachroof, there's not an inch to spare.

He was clearly content with this because fifty years and four boats later his yellow boat Yrvind.com still has the same amount of headroom. This latest boat has a ten inch draft, a flat bottom and chine runners after Layden’s designs.

I have read enough. That’s it – I’m going to have to question everything I’ve ever heard about boats and go back to the fundamental principles just like these pioneers of boat design. If anyone says what I want is not possible I might have to ignore them altogether. It seems that boating will become just like many other areas in my life – start from square one and do it my own way.

But there’s a problem. These three heroes of the sea had a lot more experience of sailing and knowledge in mathematics, physics and boat design than I do. Wharram’s background is not so clear but he certainly spent several years sailing, working in boatyards and reading up on the history of the Polynesian double-canoe. I’ve read that Layden is a professional yacht designer but I can’t confirm it – after his ten years of cruising he now appears to lead a regular family life in a house, the latest small boat designs are just his hobby-turned-passion. Yrvind dropped out of school but frequently attended university lectures in mathematics, became a school teacher, and continues to immerse himself in books about mathematics, physics and boat design to this day. For his imminent non-stop round-the-world trip he plans to take 400 kilos of food and 100 kilos of books, of which he says: “I read books in the following languages: Swedish, Danish, Norwegian, English, French, German and Mathematics.”

So what chance does a homeless piano tuner have of conjuring up a new breed of boat with such conflicting design criteria? Not much. But I have one great advantage – I have all the time in the world. Time to go sailing, learn boat building techniques and read up on design. I quote Phil Bolger:

When it comes to iceboats, I have the advantage of having had no first-hand experience at all.

I could say the same about water boats. What he means is, he is not bound by convention so can give a fresh view on ice-boat design with an open mind.

I also have other advantages: I can learn from the work of the aforementioned pioneers, I have modern materials and techniques to ease construction, I have a surplus of money for building such a small boat, I have a piano workshop full of tools, and I have several boat building experts to consult.

Is it really worth all that effort? Yes I think so. This boat could be my home for the rest of my life, and take me around the whole world. People spend thirty years of their life paying a mortgage for a house and it doesn’t help them travel anywhere, so it’s well worth investing a few years into my floating home.

Foam Core Glass Fibre Sandwich vs Marine Plywood

Following Swedish small boat designer/buider/sailor Sven Yrvind’s blog has given me confidence to consider building my boat of a foam core glass fibre sandwich composite. I had initially thought it would be beyond my capabilities. It’s essentially a glass fibre boat but with a thick layer of plastic sandwiched inside the glass that’s full of air bubbles called cells.

The only example I had seen was a large curvy hour-glass-shaped hull being built at the Boat Building Academy in Lyme Regis, Dorset by a chap called Gary from Northern Ireland. He had to loft it out carefully, build moulds at many stations then strip-plank it with thin strips of the closed-cell plastic foam core. There followed a few days of planing and fairing, then glass fibre cloth and epoxy sheathing inside and out.

However since then I had decided I should build a flat-bottomed boat with chine runners from a sheet material like plywood – this is much easier for an amateur. What I didn’t realise is that the foam core glass fibre composite is much easier to use as a sheet material in a flat-bottomed boat with hard chines. Here are some photos from Yrvind’s building blog. He uses poly-vinyl-chloride closed-cell foam made by one of the leading manufacturers, Divinycell who are in his home country of Sweden. It’s 4cm thick.


Butt-joining three sheets of Divinycell.
No joiner’s scarf joints needed – just a straight edge:
Three sheets of Divinycell foam core simply joined end to end on the floor with weights and clamps to hold them in place

Moulds:

The moulds to define the shape of the hull are stood up all carefully aligned ready for planking. It looks like they're made of MDF.

On with the hull sides:

Two long sheets of Divinycell are planked onto the sides of the moulds

He wanted a V-shape at the bow which necessitated all the extra cramps and weights.
I might just settle for a flat bottom instead:

Long sheets of Divinycell are planked onto the moulds, an array of cramps and weights ease the core material into the desired curve - the difficulty was the V-shape he wanted towards the bow.

He says he could then shape the foam core easily with a sharp kitchen knife. When he was happy with the shape, he covered it in woven glass fibre cloth and epoxy:

The upside-down hull covered in a layer of woven glass cloth and epoxy. Not yet trimmed to the sheer.

He would later do the same on the inside, completing a strong but lightweight composite hull. He has kindly shared a detailed illustrated log of his build on his website at yrvind.com/present_project – I highly recommend you read his website. He also shares the logic and principles behind his unconventional ideas, and some fun stories from the adventures of his youth.

All the above took him less than one month. The rest of the boat, including fitting out and finishing, took him a further three years. He then sailed this 15 ft boat across the Atlantic ocean last December – another great triumph for small boat enthusiasts. Here it is:

Yrvind.com - the finished boat. He's finished her in very bright yellow, with blue below the waterline after the Swedish flag. He's sailing her on a close haul in the Stockholm archipelago.

If I could design a boat with a less complex shape I might get away with less moulds, maybe even just the bulkheads, and have less hassle balancing cramps and weights. I would only really need a gentle curve on the sides and some rocker on the bottom.

What’s the advantage of foam core glass fibre composite?

The effect of the foam core and the two laminate skins is the same in principle as an I-beam for increasing strength and stiffness. It’s much stronger and stiffer than a single skin of the same weight, but much much lighter than a single skin of the same thickness. There’s a nice article on sandwich construction at boatdesign.net/articles/foam-core, here’s one diagram from that article:


Three cross sections of a hull to show the advantages of foam core laminate sandwich construction. One single skin, one with a a medium thickness core, another with a thick core. There are figures in the image showing that as the thickness of the core increases, so does the strength and the stiffness.

The strength of the hull increases up to a certain thickness of foam core (I’d like to know what that critical thickness is). The stiffness continues to increase with increased thickness. There’s an equation for stiffness on the aforementioned Boat Design website, but it’s all Chinese to me so I won’t pretend to understand it.

There are other advantages of foam core construction that I find very appealing. It’s an excellent thermal and acoustic insulator. Some of the designs on the internet for plywood micro-cruisers are not insulated, because they’re used for leisure purposes in warm climates. But insulation is paramount for me because I want to live aboard in temperate climates like in Britain.

If I build a boat out of plywood, I’ll have to cover the inside in insulation. This is standard for Matt Layden’s design the Paradox. However I’d then have to worry about rot spreading on the unventilated surface of the plywood behind the insulation, where I can’t see it to keep check. The foam adds buoyancy in the event of the cabin flooding, but it does not contribute anything to the boat’s strength or rigidity.

In a foam core sandwich hull the insulation is an integral part of the structure. It adds strength and rigidity, and being completely inert it’ll never rot. The whole hull and possibly some bulkheads made of foam core will contribute even more buoyancy in the event of the cabin flooding – with a thick enough foam core the boat will be unsinkable. I want thick insulation to make my boat very thermally efficient because I’ll live aboard all year round and I like the dramatic scenery of the high latitudes like the Norwegian and Patagonian Fjords.

A typical plywood cruising boat like the Paradox is effectively complete and sailable when the plywood is all planked up and glued. The plywood hull with its frames and bulkheads must be strong and stiff enough when naked to handle the strains and stresses of its intended use. However it needs glass fibre/epoxy sheathing, at least on the outside for rot and abrasion resistance, which does increase its strength a little more, and then a thick layer of insulation on the inside to keep it warm and stave off condensation problems. Many people would also glass the inside or at least seal it with epoxy. Each layer of the hull has a different purpose, but none of them seem to have multiple purposes, and the sum of them all is a more complex and heavier structure.

A half-complete Paradox build just after the insulation has been put in but before the deck installation.

In contrast the foam core glass fibre sandwich all works together as one structure with many purposes – strength, stiffness, insulation, abrasion resistance, compression absorption – it seems the minimum possible way to acheive all these things and of course the end result is very light weight. I imagine feeling very cosy and secure inside this unbroken, continuous monocoque structure where ever I end up cruising. I can fully understand why after fifty years of designing, building and sailing small boats in cold rough seas it has become Sven Yrvind’s favoured method of construction.

In a small boat without standing headroom the sandwich construction will give me the strength and stiffness I need to be able to sit directly on the inside of the hull, doing away with the complexity of adding floors and a cabin sole. I had a discussion about this on the Boat Design Forum here: http://www.boatdesign.net/forums/boat-design/do-some-boats-have-cabin-but-no-sole-floors-39759.html. This is possible in a very small plywood boat (see Matt Layden’s Enigma), but perhaps not quite as solid.

Unfortunately there’s a big disadvantage to the composite construction when it comes to fitting out – you can’t just put screws in like plywood planking. The foam core on it’s own is useless at taking the point loads of bolts and screws. It becomes necessary to involve a larger area of the core and both skins to support any one point load. This could be done with a backing plate or by hollowing out some of the foam core, filling the gap with epoxy then redrilling the hole. You’d better get it right the first time – I can only imagine the mess it would make if you kept shifting the fittings around over the years…

Sustainability

This is very important to me. A good quality marine plywood boat, well constructed and protected will be immensely strong and last a lifetime. That’s good enough for me, so if I’m to consider the alternative of a foam core composite construction perhaps the environmental implications will be the decider.

Being completely inert, boat builder’s PVC foam core, glass fibre and (when cured) epoxy have no effect on the natural world, but of course this means they’re definitely not biodegradable. Some argue that at least they trap carbon in an item like a boat, but wait a minute, wasn’t the carbon already trapped in the oil that was used to create these plastics and epoxies in the first place? There’s a good side to this, that if well built, the boat could last several lifetimes so there’s no need to expend the energy and resources required to replace it any time soon. But realistically, in our modern consumer culture, how many plastic goods actually do get passed down to great-grandchildren? Anyway I would hope to build my boat well enough to see me out. I’m not even thirty years old.

Marine plywood may look more natural, but cut through it and of course it’s actually several veneers of wood glued together with a weatherproof glue like epoxy. These glues are not biodegradable and give off toxic smoke when burned. But at least the veneers are natural, that’s good, isn’t it?

Not really. Those veneers in the best quality marine plywood are almost invariably mahogany from tropical rainforests in Brazil, Central Africa or South-East Asia. There’s not much rainforest left, and a mahogany tree takes five hundred years to grow to any decent size suitable for harvesting.

Mahogany trees in India - they're huge!

But there’s hope…or is there? Two famed suppliers of the world’s highest quality marine plywood, Robbins of Bristol and Bryunzeel of Holland are now offering marine mahogany plywood with Forestry Stewardship Council (FSC) certification. That said, Bryunzeel says FSC “according to available credit” and Robbins doesn’t even state the type of FSC certificate. I think I’ll treat any mahogany branded as FSC as suspicious – many types of mahogany are critically endangered, and with the little rainforest we have left I don’t exactly feel reassured by the FSC stamp that says: “don’t worry we’ll just plant another tree to replace each one of the thousands that we’ve cut down; they’ll only take five hundred years to grow to the same size and support the rainforest wildlife. No harm done.” Still, if I am to build with marine mahogany plywood I would definitely support these suppliers that have made the effort towards sustainable logging.

One alternative suggested on the UK Home Boat Builder’s Rally Forum was to use Finnish birch plywood instead. It’s touted to have many of the desirable qualities of mahogany plywood, but is grown in sustainably managed forests in Scandinavia and North-Eastern Europe, where these vast forests of the stuff are not at any risk from over-logging. Several high quality boats have been built to prove this, and the builders report the top end stuff to be completely devoid of voids. However from what I’ve read its only recommended for boats that spend most of their time out of the water because of its propensity to mould and rot. Not good for my live-aboard cruiser. It can be sheathed in glass and epoxy, but still…

Conclusion

I had been lured by the mahogany grain – it had persuaded me subconsciously that plywood was the more ‘natural’ option, whereas foam core glass fibre would be a very synthetic plastic creation too similar to the white GRP bathtubs that litter my local river for comfort. I didn’t want to be guilty of bringing more eternal plastic into this world. But hang on a minute, what’s really going on here? It’s time to take a step back and look at what these methods really involve in a finished live-aboard cruising boat:

Plywood boat:

  • Plywood hull – hardwood from tropical rainforest
  • Glass fibre/epoxy skins
  • Closed-cell foam insulation

Foam core composite boat:

  • Closed-cell foam core
  • Glass fibre/epoxy skins

A plywood boat is not natural at all, nor any better for the environment. It employs all the plastic and glass of the composite boat, plus tropical rainforest. Using a good marine plywood ie. tropical mahogany is actually very bad for the environment and will probably remain so for at least a thousand years to come. So the two boats are equally as bad, but the plywood one also involves cutting down the rainforest!

We might temper this argument by considering that not all plywood boats get glass fibre and epoxy sheathing both inside and out, and because the insulation is not structural, and the plywood offers a little insulation, less dense and less quantity of plastic foam core need be used. However a live-aboard plywood cruiser like the Paradox does use some heavy glass/epoxy sheathing on the outside for rot and abrasion resistance, and some builders also glass bits inside the boat. And don’t forget the many layers of epoxy-like glue in the plywood itself.

I’m going to have to admit that I still can’t let go of my heartfelt longing for a wooden boat. But this is a reality check for me – a plywood boat sheathed in glass/epoxy and covered in plastic insulation is not a wooden boat! A real wooden boat that has zero impact on the environment is made from solid timber – not mahogany but a wood from sustainably managed forests. If I’m not going to go to the effort of traditional solid timber construction and maintenance, I might as well build a plastic boat.

The other revelation has been that a foam core composite boat is not necessarily much more difficult to build than a plywood one. Sven Yrvind’s hard-chined build detailed above is a great example. Yes it’s more difficult to put screws and fittings in afterwards, but a lot of them can be replaced with more epoxy and foam – it’s easy to whittle any shape out of the foam and just glass/epoxy over it. There’s no need for so many beams and frames because of the extra rigidity of the sandwich structure.

Then it struck me – what if I could make my boat of recycled plastic? I asked an instructor at the Boat Building Academy about recycled foam cores because he had built foam cored ocean rowing boats and won the transatlantic race. He just looked at me like I was from another planet.

Undeterred, I spent quite a while scouring the internet, and lo and behold, I found marine-grade closed-cell foam core made from recycled plastic bottles! The construction foam giant Armacell, based in Münster in Germany, are pioneering marine-grade foam cores made purely from polyethylene terephthalate (PET) which is a 100% recyclable plastic. Most drinks bottle are made from the stuff. I was quick to email them and quick to receive this reply:

We only have “virgin” quality which means…………..not recycled.
PET as such is a foam which can be recycled …………if it’s made from a “virgin” PET raw material or a recycled raw material.
Only for very big project we can discuss about producing foam made from second generation PET.

Of course my project is very small so I was disappointed, but perhaps it’s such a new thing that they still don’t have the industries of scale to mass produce it. So it might become available to me in the near future.

A piece of Armacell foam core on a background of green leaves.

If so this would be the deciding blow against building in plywood. I think it’s brilliant that Armacell are pioneering this technology. Just imagine, a warm and sturdy composite boat made of recycled plastic drinks bottles! Now if only I could find a source of glass fibre cloth made from recycled glass bottles…

The Mast-Aft Rig

I needn’t be overwhelmed by the complications of sailing rigs – if I just built the hull I could live in it and punt it along the river, then worry about a rudder and sailing rig when I feel up to the task.

However it would be nice to know the approximate mast position before building the boat. I had some interesting thoughts about the mast-aft (or aft-mast) rig. This is where the mast is towards the back of the boat, like this:

A catamaran with a mast near the stern, raked towards the bow, and a single large foresail

It’s basically one massive foresail instead of a mainsail. The very limited number of people who have tried this rig claim that it works well.

Proponents argue that because the leading edge (luff) of the sail is not in the wind shadow of a mast, the rig is more effective to windward, and the angle of the luff gives lift.

Critics are quick to note that a bare mast creates more turbulence – coupled with the extra shrouds and stays it creates enough windage to negate the advantage of the clean luff. There’s also a tug-of-war going on between the forestay and backstay putting more stress on the hull. And it doesn’t look very good for downwind sailing.

However I’m not interested in this rig for for any performance advantage – there may be more practical advantages. First for ease of handling the sail – it can be self-tacking. and roller-reefed/furled around the forestay just like a jib. The sail control and mast would all be at arm’s reach from the hatch on the design I drew in the last post.

The key advantage would be when lowering the rig to pass under a bridge. Instead of using so many shrouds, I would make the mast a tall ‘A’ shape – effectively two thin masts joining at the top. Even more windage, I know, but there’s a good reason. They would each be fixed to the gunwales in the cockpit with hinges so that the A-mast can be lowered forwards. A micro-cruiser should have a rig with a low aspect ratio, which is convenient because this A-shaped mast will not be any longer than the boat, and so could be lowered forwards over the coachroof/cabin area and rest flush with the foredeck, the peak of the mast right on the tip of the bow. The raised cabin roof will then protrude through the middle of the A-shaped mast.

The A-shaped mast doesn’t need shrouds to take lateral loads, it only needs a back-stay and a fore-stay around which the sail gets furled. Between them they hold the mast at the desired angle of rake without needing to fix its position by any solid structure. To pass under a bridge I just use a quick-release on the back-stay.

The centre of lateral resistance on a boat with chine runners and a large rudder is further aft than on a conventional boat, so if the boat is long enough the mast-aft rig might put the sail in the right place. But on a shorter boat, if placed far enough from the stern for the back-stay to support it properly, I’m not sure the centre of effort will be far enough aft to balance the rig, and I might end up with the dreaded lee helm. When I reef the sail in high winds I might get even more lee helm.

I think I need to draw this up someday to get an idea if the rig is realistic. There must be a reason why nobody uses it! I’m not expecting it to perform any better than Matt Layden’s balanced lug-sail rig prevalent on micro-cruisers, and it’s probably rubbish downwind. But I just don’t see how the lugsail rig and unstayed mast would lower as flush with the deck as the mast-aft A-frame idea.

Microcruisers and the Chine Runner Concept

I was first introduced to micro-cruisers in December 2010 by a helpful reply from Tom Lathrop of North Carolina to my question on the Wooden Boat Forum about seaworthy boats that have a shallow draft. Thanks Tom!

microcruising.com has lots of great information about microcruisers, and details some of the best designs out there and the history behind them. The author, Dave Bolduc, has cruised microcruisers extensively with his wife Mindy and two parrots. On the website he defines micro-cruising thus:


“In my mind I always thought of a micro-cruiser as a small boat whose primary purpose was for cruising. I believe its design should provide shelter for its crew from the elements, and it should be capable of carrying sufficient stores to complete its intended journey. In fact, it should mimic the function of a larger cruising vessel, but it should do it on a much smaller budget and on a much smaller scale. I think it would be safe to say that most micro-cruisers are probably less than 18 feet in length; though, some might call the larger boats “pocket cruisers”… …So what is a micro-cruiser? It’s a small affordable boat that let’s the average person like you and me go cruising.”

Here’s Dave and Mindy with Matt Layden, the designer of most of the boats on their website, in the Bahamas:

Two flat-bottomed micro-cruising boats beached on the white sand, three sailors stand by

Matt Layden’s micro-cruisers are unique for having no cockpit, a flat bottom and chine runners.

In a boat less than fifteen feet long, the cockpit would be too small to be useful, and so would the cabin. In the words of the great designer Phillip Bolger:


“Even in much bigger boats, dividing the space into “below” and “on deck” means that both suffer. I look for a way to combine the functions, to use the whole boat day and night.”

Without the low cockpit area the boat has much more buoyancy high above the waterline, making it less stable upside-down and more likely to self-right. This is of special importance to a boat with a shallow draft and flat bottom that doesn’t have a deep, ballasted keel. Phil Bolger again:


“High freeboard is an efficient substitute for low ballast.”

The flat bottom makes the boat much easier to construct from sheet materials like plywood, opening up boat-building to amateurs like me. It also adds a lot of initial stability, and interior space. Most importantly for me, for any given displacement a flat-bottomed boat will have the most shallow draft, so I can get in near the beach or access rivers and backwaters that are inaccessible to larger craft.

The chine runner concept

A thin tab of wood protruding from the chine of a flat-bottomed boat, running lengthways along each side

The photo above shows a chine runner on George Van Sickle’s Enigma 460 micro-cruiser prototype. The chine runner concept was invented by Matt Layden of Florida in the 1980′s as a way to provide resistance to leeway for a sailing boat without a keel or foils such as a centreboard or leeboard. The benefit is that the boat can sail in very shallow water and there are less moving parts to move around or get broken. It doesn’t take up any space inside the boat.

The chine runner itself is only a small part of the resistance to leeway. It’s actually the hull and the rudder that provide the main resistance to leeway – the chine runner just increases the effect of the hull. Anyone who has sailed a flat-bottomed punt will confirm that you can sail on a close reach without the need for a centreboard or leeboard. The long, flat side of the boat provides some lateral resistance.

Matt Layden’s designs feature plenty of rocker on the bottom. When the boat is sailing to windward it heels over, and the rockered bottom is to windward. The curved bottom experiences lower pressure from the water, the side of the hull to leeward experiences higher pressure, creating lift to windward just like the aerofoil effect of an aeroplanes wing. The chine runner accentuates the effect by creating a fence between the high and low pressure.

Because this is not as effective as a deep keel, the rudder is made bigger to compensate by providing more lateral resistance. As an added bonus the helmsman has more steering control.

I like the chine runner concept for the same reason Matt invented it – it enables a shallow draft boat to sail to windward without any complicated or moving parts. This also frees up space in the cabin. Some boats with deep keels can sail closer to the wind, but is all the extra complication and deep draft worth it for just a few degrees closer to the wind? For racing maybe, but not for leisure cruising. In the words of Matt Layden:


“..in my opinion it’s the whole system: hull shape, chine curvature, chine runner shape and size, and a good, big efficient rudder carrying a lot of the side load that makes these boats sail and steer well. I don’t claim to understand the finer points real well, but these boats do work – that is they generally outsail any similar sized moderate displacement boat they come across, upwind or downwind, zephyr or gale.”

The chine runner concept is potentially a revolution in sailing boat design, but even after thirty years it remains little-known. Many suspect that the industry is not interested because it hasn’t been tested on big boats (that sell for big money), and also because the yachting industry follows yacht racing closely. Racing yachts are deep-water boats with deep, ballasted keels and foils, which are pretty useless to the average cruiser because they can’t go anywhere near land for fear of grounding in shallow water.

Also Matt Layden is very quiet-spoken and has no interest in touting his invention, or patenting it as far as I’m aware. However he has been kind enough to share one design, the Paradox, and explain the concept to anyone who asks, for example in this great interview for the Small Craft Advisor magazine. Here’s a photo of the Paradox this one’s called Little Jim built and sailed by Alistair Law here in England:

A little green sailing boat with a tanned, balanced lug-sail rig on a close haul in what looks like Lake Windermere or somewhere similar.

The only thing I’m not keen about on these micro-cruisers are the limited options for propulsion: sail or single sculling oar. Alistair complained of blisters and doesn’t like sculling any more than is absolutely necessary. Matt Layden himself had a sore wrist on his sculling arm for most of the 2006 Ultimate Florida Challenge 1200 mile race. Even with a small boat like a micro-cruiser, sustained sculling speed is limited to about two knots, and three at a sprint. I’d like to have several other options for human-powered propulsion. Whether or not that’s possible is another question – surely if it was so simple Matt would have incorporated it into his design.

My First Design

When I first learned of micro-cruisers I immediately thought they’re way too small for me to live in. But that was when I rented a flat. Having now lived homeless for quite a while and enjoyed the experience, a micro-cruiser would be more than enough space.

Matt Layden’s Paradox design is a potentially good floating home for me. However, for my intended cruising haunts there are several problems with it. Firstly it’s too heavy – in sailing trim it displaces about 650 kilogrammes – I was hoping for something much lighter to be able to pull it out of the water on wheels and cart it around. There are many beautiful stretches of river in England that were once navigable but have since been blocked by man-made structures such as very low bridges and weirs. How thoughtless. If I could cart my boat around such obstacles it would open up some really unique places for me, including waters that have always been cut off like the lakes of Cumbria or Patagonia. It would also be much easier to drag my boat up above the high water mark on the beach.

Paradox is described as a “coastal cruiser”, designed for cruising up and down the east coast of the USA. I will spend a lot of time on rivers and canals that rarely have a decent, steady wind, so will have to rely on the single sculling oar (yuloh) for propulsion, which could quickly become tiring. I want more options.

Paradox doesn’t have a cockpit. But hang on a minute, isn’t that the whole point – a small boat is better off without a cockpit to increase cabin space? Well yes, but without a cockpit it would be difficult to punt or scull with two oars. And in the sunny sheltered waters where I spend most of my time, I’d like to be able to sit outside to navigate.

It was around about this time that I became overwhelmed by the scale and complexity of the project. I’m not even an amateur, I’m a complete beginner. I’ve never deigned or built a boat before, let alone sails, rigging, rudders, windows… oh how I wished that I could just buy the boat I dreamed of and go cruising! But alas, nobody makes it. And so far it seems nobody’s designed it either. Thankfully I received encouragement from the opening line of the yacht designer John Teale’s “How to Design a Boat”:


“Anyone having a reasonable eye for a fair curve and the merest smattering of mathematics can design a boat. The first effort may not be a world beater but, if built, should perform perfectly well and give a good deal pleasure.”

Perhaps I should build a human-powered riverboat after all, and from the learning experience build a sea-going boat later. After all, for the next few years I’ll probably stick to the Thames Valley, going up and down the beautiful river. I made my first ever drawings, based on a punt with square bow and stern and a cabin. Then I found this webpage where Matt Layden details the construction of his lightweight micro-cruiser, Enigma, which was made of 9mm/6mm plywood, glassed, displacement c.420lb, LOA 12′ beam 3’3″ draft 6″:

A few sheets of plywood coming together to form Enigma's hull

Enigma - the finished boat sitting on wheels.

I took great interest in this boat for two reasons. First it was so simple to build using the stich & tape plywood epoxy glueing method. Secondly because it was exactly the kind of size and weight range that I wanted. This sharpie shape, with a pointy bow for chopping waves, would give less underwater volume for a given waterline than a box-shaped punt. This was good because my drawings showed that I’d need an awful lot of weight to get the boat to sit deep enough.

The chines need to be at least five inches or so underwater for the chine runner concept to work. With a bit more weight comes a bit more inertia, and more bite in the water so as not to skitter around on the surface. Less boat underwater means more boat above the surface being blown around by the wind like a piece of polystyrene. I had initially wanted the most shallow boat possible, but if I wanted a narrow beam boat weighing at least 300 Kg including me I’d have to accept a draft of at least six inches, which I need anyway for the chine runners to work.

With a pointed bow, why restrict my design to the rivers? I might as well go back to the drawing board for a boat that could sail rivers and seas. So that’s what I did:

A pencil drawing of a sixteen foot long sharpie on squared paper

I’ve since realised that the convention for drawing boat designs is for the bow to point to the right. Oh well. This first rough idea is based on the following criteria:

  • 4′ cockpit for double-oar sculling
  • single-oar sculling
  • punting
  • 4′ max beam
  • 4:1 length:beam ratio
  • 3′ headroom
  • 6″ draft and the chine runner concept

The cockpit is four feet long in the stern, the sliding seat is recessed under the cockpit sole. The boat became 16′ long with a draft of 7″ at a displacement of 450Kg.

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Dream of boats

I dream of boats

The Dawn Treader, a square-rigged sailing ship shaped like a dragon.

My childhood dreams of boats were much inspired by the fantasy and adventure stories I read, for example The Voyage of the Dawn Treader and Swallows and Amazons. I lived in Portsmouth, and often gazed out from Southsea beach at the Isle of Wight and wondered about France and other unknown lands over the horizon. I also studied a small globe, noted that most of our planet is water, and was curious about what it would be like to explore remote islands. Mostly my dreams consisted of a large, heavy, traditional solid timber sailing yacht or square rigger running deep turquoise tropical seas that sparkle in the warm sunlight, cutting through mountainous bays and inlets then disappearing over the horizon.


A traditional sailing ship

Naturally I had many other childhood dreams like climbing Everest and snowboarding down it, scoring hat-tricks for England in the football World Cup, and flying into outer space to meet aliens, all of which I thought was perfectly feasible.

My only experience with boats was the car ferry from Portsmouth to Le Harve in France, a six hour journey that I always enjoyed immensely, spending most of the journey up on deck even in poor weather. I remember when we moved up to Oxford then took the Dover – Calais ferry for the first time. My parents remarked how quick and convenient it was, but I was so disappointed that we only spent one hour on the English Channel.

A P&O car ferry - it's huge.

Aged twelve I did a three day course of dinghy sailing in Langstone Harbour. I soon forgot about it as none of my family or friends were into boats and I had no further opportunity to experience the water. I only really remember the last day, when we sailed our little plastic dinghies right down to the harbour entrance and poked our bows out into the Solent. The waves were two or three feet and the wind was strong, so we quickly retreated back to the sheltered waters.

Sailing a dinghy with a friend in Spain.

After moving to Oxford, aged thirteen I got one afternoon dinghy sailing on a reservoir in Spain, and a couple of hours in punts on the river Cherwell. I missed the sea but this charming river flows into the Thames near my parents’ house and there are a lot more green open spaces than in Portsmouth, so I soon got over it. I often walked or cycled by the river and it became my quiet place of escape. I would follow it, always wondering what was around the next meander.

Looking towards Rose Island on the River Thames at Oxford. Several white plastic boats are moored on the east bank, but a lovely large old house and willows adorn the island.

School, university, family business and affairs took over my life and my childhood dreams were locked away for fifteen years.

I need a boat

Aged twenty-two I moved to London and established my independence, but after a few years I grew tired of paying extortionate rent for shabby places and having to deal with a mixed bag of landlords and tenants. Every time I moved flat I kept an open mind and looked out for alternatives. I noticed big barges moored up on the tidal Thames and was awed by the amount of living space they had, more than a four bedroom house, and no rent to pay. But the price of the huge boats and the cost of their residential moorings was hundreds of thousands, way out of my league.

A black and yellow barge with a family standing on deck

I turned to the canals and looked at narrow boats, which are the most popular live-aboards in this country. I couldn’t afford one – I needed £20,000 but I was actually £20,000 in debt. I also thought I would need a residential mooring costing up to £5,000 per year. Like many young people trying to take their first steps in life, after the initial excitement I was put off by the expense and shelved the idea.

A green narrow boat

I’m very lucky to live in the age of Internet. I would occasionally scour the web for people who had found a cheap alternative way of life. I found some people who had escaped the city, built a cabin or yurt in the wilderness and lived off the land. Others living in cars, camper vans, and of course many on boats. I began to consider living in a tent. I also discovered that small second hand sailing yachts were available very cheaply in Britain, that I could buy something habitable for less than £3,000 and it could potentially take me much further than any narrow boat or barge.

Previous generations used to sail a lot more, now there are many fantastic sailing yachts sitting around doing nothing – click here for some amazing bargains. For example this tough little bilge keel yacht made by Hurley Marine, one of the most repected British designers and builders, is going for just £1,400. The seller says: “Good condition example of this popular sailing boat! Tough little seagoing yacht built by Hurley Marine Plymouth with very high manufacturing standards. Comes complete including main Sail, storm jib, genoa 2 spinnakers. Navigation Lights, pull Pit And push pit, compass, Bruce anchor and chain, NASA log/depth sounder, Battery, Life Jacket. Johnson Seahorse 4HP outboard. Llyods production certificate. 2 berths in 2 singles. Antifouled ready for the boat season.”


A little yacht with bilge keels laid up on the hard

Around this time I read the story of The £200 Millionaire by Weston Martyr (if you read it, Zeeland is an area on the coast of Holland). It’s a story about an old bloke who had lost most of his family and the will to live after the First World War, but found new life and happiness by giving up everything and retiring to live on a little green sailing boat to explore Europe’s infinite waterways. It has since encouraged many people to follow suit all over the world, and I was no exception. I already had a good feeling about living on a sailing boat, but this old man put it all into words and made it such an obvious lifestyle choice.

But the more I learned about boats, the more fussy I became about my future floating home. I wanted a boat that could sail the ocean and yet still navigate small rivers and canals. I had also become much more aware of how much I was damaging the environment, so I decided I didn’t want to have a combustion engine, instead I wanted a boat that could be moved around using human muscle when the wind didn’t serve. This would be free, and give me compulsory exercise every time I wanted to move.

I must’ve done a thousand hours of research on the Internet by now, and enjoyed every minute of it. I read so many people complaining about big boats and how much they cost to maintain, and to pay for mooring and marinas. They often have a deep draft so have no choice, and have no chance of accessing the most beautiful shallow waters next to the coast or up rivers and canals. I wanted a small boat with a shallow draft, easy enough to propel at a decent pace with my own muscle, but big enough to live in comfortably. These qualities are not very compatible – here’s a link to two very interesting discussions I had on the Wooden Boat Forum and the Cruisers Forum, which I now find quite embarrassing to read but you can see that I was getting fussy – no boat was good enough.

I realised the kind of boat I wanted was not in production, so I’d have to build it. I might even have to design it, which among boating circles is considered a very silly thing for an amateur to do. I spent all my savings on a few courses at the Boat Building Academy in Lyme Regis, and I’ve never regretted it – in the month I spent there I learnt many ways I shouldn’t build a boat and got some great ideas for how I should go about it.

Some finished boats in the workshop at the academy. A strip-planked canoe in the foreground.

I grew impatient, and despite not having much money and no boat I decided to stop paying rent and become homeless. I reasoned that even if I didn’t get a boat, I’d get some valuable experience living outdoors, after which living on any boat would surely seem luxurious.

When I first moved out of rented accommodation I had lived in centrally heated buildings all my life, where I could stand up and walk around. I had a toilet/shower room and a kitchen. So when I thought about living on a boat, I naturally imagined a boat big enough to have all these things. But I knew that a big boat is a big liability, so I tried to find the compromise between having enough living space and having a small, simple boat that was easy to manage.

I just want a boat

The last year of happy homelessness had taught me that I don’t need this. I don’t need a building to stand up in, a private shower room or a kitchen. I don’t even need to cook really. In cold times I can shower at a sports centre, warm times just jump in the river. I can put a warm coat on and stand up outdoors. And run and jump too.


Me sleeping rough on a jetty above the River Thames

So what do I need a boat for? Good question. When I left rented accommodation I thought I needed one to live in, but now I’m having second thoughts… now I’m happy living with nothing but a bicycle and a bag. A boat might be a burden, it might be a material thing that I get seriously attached to, and worry about when I have to leave it somewhere. I conclude that I don’t need a boat. But I do want a boat. For some reason, I can’t stop thinking about boats.

I want a boat because there’s something special about water – be it sea, river, lake or canal – highways of peace through our busy world, Mother Nature concentrated in timeless, deep pools of reflection. A look at most paintings and postcards of landscapes will reveal that open water dominates the most beautiful scenery on our planet. A boat would also be convenient to carry water and food bought in bulk, means to cook it all, and other useful things like tools or a snowboard. It would be convenient to not have to seek warm, dry, public places to hang out in poor weather and hidden, sheltered spots to sleep every night – a well insulated boat cabin could give me both. It would also be safer than sleeping rough because I can anchor away from the shore or moor to places inaccessible to troublemakers.

Another reason I’m interested in a boat propelled by human/wind power is because I’m not sure if my knees can handle much more cycling, especially cycling around the world. And the freedom of a seaworthy sailing boat has great appeal – to be able to sail anywhere in the world without a ticket, in my own time, regardless of whether or not there are transport links.

There’s more detail on the reasons why I want a boat on my introductory boat page, but I mention them here because they must define what kind of boat I choose. When I left my rented flat I thought I needed a boat for a home. But now I realise this is not necessary, because I can quite happily live outdoors. So given these revised reasons why I want a boat, what kind of boat should I be looking for?

Well it obviously doesn’t need to be nearly as big as I thought. It doesn’t need a galley (sailor-speak for kitchen), or a seperate toilet/shower room. I can cook on a camp stove, and as I’ve discovered in the last year I can jump in the river for a bath, go to a sports centre or use some of the free showers that are available. Alternatively hang a water bag from a tree and shower under it. And where there are no public conveniences I can keep a little porta-potti or portable composting loo.

I don’t need standing headroom. I can go outside my boat to stand up. When sharing my ideas for a floating home some people were adamant that it would be horrible to live on a boat all year if I couldn’t stand up and walk around a bit. However I’ve now been homeless for over a year and enjoyed it, confirming that anything I can’t do inside my boat, I can just do outside.

The key to this is either keeping busy at work, or travelling somewhere warmer. In the Winter if I’m working full-time I can stand up indoors at the workplace. If I don’t have work there’s no point in staying, I might as well sail south to the warm Winter of the Mediterranean or the Caribbean. That’s what the real cruisers do, just sail where the sun shines.

So all I need from my boat’s cabin/saloon/berth is a warm, dry place to sit and lie down. Sitting on a chair I need four foot headroom, sitting on the floor only three feet. If my boat is to be wind/human powered, it’s very important that it’s as low as possible. A high freeboard and air draft will mean the boat has more windage, it’ll get blown about and be difficult to control. Larger boats often overcome this with a powerful engine, but I don’t want one for the same reason that I pedal-cycle instead of motor-cycle. I’d rather sit on the floor and save myself the trouble.

But what is the floor? Conventional boats have a cabin sole to walk on, under which there’s a storage space, under which is the boat’s hull. This can be important to distribute loads evenly on the hull, especially in traditionally planked boats. But modern sheet construction methods can eliminate the need for a sole especially if it’s a very small boat. I got some helpful replies on this subject on the Boat Design Forum.

I want my boat to be small and shallow enough to go up rivers and canals, but seaworthy enough to cross an ocean, if such a boat exists. My priority is comfort and efficiency on sheltered waters, and safety at sea. Note that I don’t expect to be comfortable or efficient out at sea, just safe – I expect to spend over 99% of my time in sheltered waters. In fact 100% of the time until I have a few years’ experience.

If I don’t intend to strike out across the Atlantic any time in the next few years, why do I want a seaworthy boat? I don’t really need one now. Well I don’t see the point in learning how to build several types of boat with several different techniques, when they’re not ultimately the kind of boat I want. For example in December 2010 some people suggested I stop dreaming and talking and get on immediately with building the Escargot designed by Phillip Tiel (pictured below). It would have been a comfortable boat, with standing headroom, and it’s pedal powered. I would have learnt a lot in the construction process.

A little barge with a bloke pedalling in the stern cockpit

However it might have taken me a year to build and fit out, by the time I finished it I’d want a completely different boat. With such a high freeboard it has so much windage that I’d get blown around all over the place. In fact there are a fleet of these on the river Ruhr in Germany, when the wind picks up they have to use an electric engine to go upwind. It’s a 6′ wide and weights a ton, made for two peddlers and to host several people. It’s designed for calm, sheltered canals, with no current, where it would be an ideal home, and very comfortable too. But I want more of an all-round boat. I want to be able to sail too.

I ignored these suggestions and kept researching, and in the time it would have taken me to build it, I learned to be homeless instead, which I consider of much greater value. In fact in researching and thinking over the last couple of years, without building or buying any boat, I’ve saved myself vast amounts of time, money, and headache. If I’d taken everyone’s suggestions I’d have several boats by now, and I would have used a lot of natural resources too. I enjoy building things but I don’t want to dedicate my life to boat building, what I really want is to go cruising, in the right boat. So just by thinking I’ve saved a lot of time, money and natural resources, and in the meantime have learnt to live homeless with no possessions. This is turn has made me realise that I’d be happy in a much smaller boat.

I also appreciate that in design it’s normal to make several boats, prototypes, before getting something that works. My boat will be small and relatively cheap – I’m going to build it like a finished product, then if I’m not satisfied it’ll become a prototype. And there’s still the hope of finding a suitable boat designed by a professional naval architect. I refuse to be put under pressure to get involved with any boat until I feel the time is right. I will continue to research and think about it until I happen on the ideal design – this will save a whole load of hassle.

I want the boat to be as small and light as possible. Not only will this enable me to explore little rivers and creeks that are inaccessible to larger craft, but I’d also like to be able to drag her out of the water on wheels to portage around obstacles. It would be brilliant to hook the boat up to my bike so I can tow her to inland cruising grounds, like lake Windermere, for example. Sound wacky? Maybe, but it’s definitely possible with a small boat weighing less than half a ton.

I want the boat to sail, but the mast must be easy to lower to get under bridges. There are many very low bridges on the canals in England. One of my dreams is to be able to sail where no boat has sailed in the last hundred years. For example on open stretches of the River Thames, some of which have sailing clubs but on the majority I’ve never seen a sail ever. It would be helpful if when the mast is lowered, it doesn’t interfere with the human-powered propulsion.

A Human-Powered Houseboat

How would I propel the boat using human power? Well the strongest muscles with the most endurance are the legs, and there are many examples on the Internet of people who have developed pedal drives for boats. However, I do want to give my legs a break from all the cycling. Sculling with two oars and a sliding seat is the most powerful method of propulsion that uses the whole body. Then there are other methods that mostly employ the upper body, such as punting, paddling, and sculling with one oar.

Many of these methods for propulsion present some complication to the design. To scull efficiently with two oars, there must be an open cockpit at least four feet long for the sliding seat, with the rowlocks not too high above the water. Ideally this should be amidships like the ocean rowing boats, but it might work in the stern although it would be more difficult to steer. Alternatively I could sit inside the cabin and the oars could pass through holes in the hull, with flexible sleeves to stop ingress of water. Here’s an example, a design by Phillip Bolger for a live-aboard ocean rowing cruiser:

A photo of the curious torpedo-shaped boat with a little windowed deckhouse and oars sticking out of the side

A drawing of the curious torpedo-shaped boat with a little windowed deckhouse and oars sticking out of the side

See specifics of the design in his brilliant book Boats with an Open Mind. The chap he designed it for enjoyed many cruises on Lake Michigan. He eventually set off across the North Atlantic and apparently enjoyed the adventure of a lifetime – he almost made it but his boat was found empty off the west coast of Ireland; he was declared lost at sea. Not to dampen my excitement about boating, but there are many stories like this to help sober me up. No ocean for me, at least not for a long time, and not without the right boat. Still, at least this man lived his dream, at a healthy old age after many years obsessing over it he just had to go out to sea. Others have taken the risk and survived.

I digress – passing the oars through the hull is a novel idea, but I’m not so keen. In calm waters I’d rather be sculling outside than in a hot sweaty cabin, which would be a bit pants on a quiet river in the summertime. And if I ever made it to rough seas where it would be preferable to scull from inside the boat, I would imagine it’d be very difficult to maintain enough balance to scull efficiently anyway.

I also don’t like the open cockpit amidships that the ocean rowing boats have. I mean, it’s a great design for an ocean rowing race, but I don’t fancy living aboard. Because they sit amidships to scull, the accommodations must be separated into one cabin at the bow and another at the stern, usually one for sleeping and another for storage unless there are many people in the crew. There are more hatches to store supplies under the sculling area. I don’t want so many hatches, or to separate my living accommodation from my storage. Add all these features together and you get, for a single oarsman, a 20′ boat with a 5′ beam, much bigger than I want, and no other options for propulsion. But they’re perfect for rowing across oceans! Here’s the record-breaking Englishwoman Roz Savage, the first woman to row across three oceans, in her ocean rowing boat:

Roz Savage rowing in her ocean rowing boat

So the only way to incorporate sculling with two oars and a sliding seat into my design would be to have an open cockpit at the back at least four feet long, with enough space behind the sliding seat to lean back and get the full range of motion for maximum power output.

This cockpit could also be used to stand and push the boat along with a pole (punting). This is a beautifully simple way to move a boat in waters as deep as 20ft, and is perhaps the best way to stay against a strong current, because you’re not pushing water but the actual river bed backwards, giving you a really solid platform to push against.

I exchanged some emails with the legendary boatman John Eade, author of the website Thames.me.uk, and he recommended at least three feet lengthways to stand in for punting. He also suggested that I should try to make the boat as long and thin as possible, with a length:beam ratio of at least 4:1 – this would increase speed and directional stability when compared to a short fat boat.

I’m very attracted to the idea of punting my home around. It’s the most ancient, Spartan way of moving a boat and unlike double-oar sculling you can actually see where you’re going. In September 2011 I punted up the River Cherwell from it’s confluence with the Thames in Oxford as far as I could go, until I was blocked by a fallen tree near Kidlington. I discovered that it’s exactly the kind of exercise I hoped for – I felt I had given a really thorough workout to all my core muscles, abdominal muscles, back and arms. Here’s a typical leisure punt:

One young man pushing a wooden punt from the stern with a pole, another paddling at the bow, and a young lady relaxing amidships.

A single sculling oar could probably be incorporated to most designs. It may not have the pushing power of punting but in deep, still waters can be just as fast, especially if the punt pole’s out of its depth. All I need is a pivot point on the stern. Here are some videos of sculling with one oar:

Pedal power is not so simple to incorporate. There are two common ways to transfer pedal power to the water: a propeller or a Mirage Drive. The Mirage Drive is a nice simple system patented by Hobie, the North American kayak manufacturer, that transfers a back-and-forth movement of pedals to a side-to-side flapping of underwater fins or flappers. It’s best described by another video:

Many reviewers have said it requires less effort to maintain speed than a pedal-propeller drive. However the human-powered water 24-hour record is still with a prop-drive – 151 miles.

I’d love to be able to propel the boat with one of these pedal drives from inside the boat in poor weather. It would be especially helpful when it’s raining or there are big waves but no wind. However there are major problems with both. The Mirage Drive would require a big hole in the bottom of the boat. It could have a raised trunk to prevent water from filling the boat, nonetheless I would not want a big hole in the hull of my nice warm, dry, insulated cabin. Especially not out at sea. The other issue is damaging the drive when beaching – I’d like to have a strong, robust hull bottom and not worry about shallow water or where I beach the boat.

The propeller drive would also require a hole somewhere for the transmission of energy from the pedals to the propeller, however this would be easier to seal as it’s just one rotating shaft. It could also be above the waterline with a flexible propeller shaft down the side of the boat. But a propeller can be worse than a Mirage Drive in shallow water and is terrible for picking up weed.

Either pedal drive will take up some space in my cabin. Being my first ever design or build, I think a pedal drive is adding too much complication and I should perhaps leave it out for now. Pity though, because the leg muscles are powerful and slow to tire, and it would be nice to be able to propel the boat whilst hiding from bad weather.

Electric propulsion

Electric propulsion has received new interest in recent years for its almost silent operation and its potential to be carbon-free. I met one chap moored up on the Thames towpath in Oxford who’s smart blue narrow boat had nothing on the roof but solar panels. When his battery was charged he moved the boat with an electric motor. For heating he used a wood burner, so effectively he had the luxury of a large living space at no cost to the environment except the initial construction and maintenance of his boat.

Still, I want to reserve any power gained through solar panels for other uses, and a small boat won’t have much space on deck for panels anyway. I want the exercise of moving my boat around using my own muscle although I appreciate that in certain conditions the current may be too strong against me. Anyway I won’t be not in a hurry to move my boat, so I’m going to design the boat for human-powered propulsion, then reconsider supplementing with an electric drive afterwards if needs be.

In conclusion, to keep it simple I’m considering propelling my boat by punting, sculling with two oars, sculling with one oar over the stern, and of course sailing.