A proa is a double hulled vessel with all or some of the following attributes:
- The rig is mounted in or on a hull.
- The hulls are frequently different lengths and shapes.
- Steering and leeway prevention are also in one hull, generally but not always, the same one as the rig. Steering can be achieved by rudders, paddles, oars, crew movement and fore and aft movement of either or both of the centre of effort, or centre of lateral resistance. Leeway resistance can be provided by hull shape, leeboards, daggerboards or oversize rudders.
- They are able to sail in either direction. This generally involves shunting (the equivalent of tacking or gybing, see diagram), although as with most things proa, there are numerous variations of this as well.
All these variations indicate that the ultimate proa is yet to be built.
Proas were probably the first improvement made to a floating log by early sailors. A second, smaller log was lashed to a cross beam to stop the main log capsizing. Rigs were added later when technology allowed. These boats have been scattered through the Pacific and Indian Oceans, where they have been undergoing development for hundreds of years. Consequently they are very highly developed for their conditions of use, and the materials they are built from. They sail in generally warm, trade wind conditions with crew who are not only fit and agile, but are superb seamen. They range in size from small models ballasted by baby coconuts up to large ocean crossing vessels capable of carrying a dozen people and their supplies for many weeks at sea.
However, they are by no means the end of the story. Our ancient Polynesian cousins had no access to epoxy, fibreglass and carbon plus they seldom had to sail upwind in less than idyllic conditions crewed by the wife and kids and driven by the need to be back at work by Monday morning. If they had, then their boats would be far different to what they are.
Western sailors have been slow to adopt proas. This is partly because until now they were difficult to manoeuvre, and partly, I suspect, because many people are unhappy with boats which are not symmetric fore an aft. They received a brief burst of publicity after the 1968 Singlehanded TransAtlantic Race (OSTAR) when the 12m/40′ proa Cheers achieved 3rd place. Cheers was designed by the legendary Dick Newick and was a masterpiece of elegant simplicity. It was sailed by Tom Follett, arguably the best, if not the highest achieving, yachtsman of his time. Cheers was different to traditional proas. It had the rig, rudders and accommodation in the windward hull and looked like a double ended trimaran with the windward float missing. The benefits of this set up are reduced weight, windage and stress of a second set of beams and a third hull and the weight of the rig and foils are all in the best place to enhance righting moment. To differentiate between traditional and Cheers type proas, Newick coined the term Atlantic Proa for proas with rigs, rudders and accommodation in the windward hull. By default, traditional proas scored the prefix, Pacific.
Cheers was schooner rigged, with heavy, wooden, unstayed masts. She was narrow by today’s standards at 4m/13′, had a conservative sail area and was a pig to shunt (more later on this term). She also had inadequate freeboard at the bow, making for dangerous running in big seas or strong wind. Despite these faults, Cheers showed what could be done and started a rush of proas, mainly by the French singlehanded crowd. These 2nd generation boats suffered a rash of misfortunes, mostly caused by sailors running before they could walk. After numerous capsizes and DNF’s, they were banned from short handed yacht races in Europe.
This was similar to the experiences of early cats and tris, although compressed into a much shorter time period, and with the added pressure of very rapid development of other multihulls making the proas look relatively slow. An exception to this was Crossbow, the 60′ proa which held the world speed sailing title of 31 knots in 1975. Crossbow was very specialised. It only sailed in one direction and had to be towed back after each high speed run. There was also an 18m/60′ long by 24m/80′ wide aluminium proa built for the Rhoute de Rhum singlehanded transatlantic race in 1982 . This boat had a single beam supporting a waterballasted windward hull. The beam could be raked aft to keep the bows up in hard reaching conditions. The maiden voyage was out to the race start, and the skipper inadvertently (possibly with an eye on the gales forecast for the first night) released the rope which held the beam in place. It folded in against the lee hull and the boat capsized.
Cheers has been refitted by some French enthusiasts and is sailing in the South of France. I have no idea what happened to Crossbow, but suspect it is sitting in a shed somewhere in Eastern England. The French monster has, unfortunately, probably been melted down for scrap.
After the ban, interest in proas died out apart from the Pacific Islands where life carried on much as before, although outboard motors replaced sails on a lot of boats. Recently however, there has been an upsurge in interest, mostly people building replicas of traditional proas using modern materials. These tend to be more efficient than the traditional boats, but still have many of their shortcomings. They lack righting moment without large crews, their crabclaw sails tend to be lousy upwind, and because the masts need to be moved from one end to the other, they are slow, cumbersome and dangerous to shunt.
A few people have appreciated and used the reduced stress and materials inherent in proas to build and cruise cheaply. Among them are a couple of French cruising proas sighted in various locations around the tropics, but information on them is hard to come by. Russ Brown (Jim of Searunner trimaran fame’s son) has designed, built, and cruised extensively in Pacific proas, although he is loathe to sell plans or to encourage others, perhaps less skilled, to follow in his footsteps. His current boat, Jzerro spent a winter in Brisbane after being cruised from Seattle via Tahiti and Noumea. It was then shipped back to Seattle.
One of the most travelled proas is in fact Australian. Designed and built by Blaz Kokor in 1980 , About Face cruised the East coast of Australia, before being bought by it’s current owner, Ted Lamont, who cruised, frequently singlehanded from Tasmania to Perth, a journey of some 5,500 miles.
One of the theorists who appreciated the advantages of a proa was Joe Norwood, who wrote about them in his book High Speed Sailing. Norwood appreciated that Atlantic proas placed relatively high stresses on both the masts and the beams, and that these stresses could be reduced by placing these components in the lee hull, as in the Pacific proas. Unfortunately, he confused the issue by adding the complications of hydrofoils which worked in both directions, and the theoretically impressive, but practically very draggy, pyramid rig. None of his proas were built.
What all these proas had in common was that to a greater or lesser degree, they were slow (frequently built to trimaran specs, not appreciating that the loads on a proa can be far lower), and had rigs and steering which made shunting far slower than tacking on a conventional craft. Until these obstacles were overcome, proas were never going to be taken seriously.
I built my first proa in 1992 using stitch and glue ply, an alloy mast and a bewildering variety of steering combinations. At 5m/16′ long, this was competitive with Lasers and slow beach cats, and taught me many lessons about sailing proas. It was followed by U, a 7m/24′ proa with carbon/foam hulls, carbon mast and beams and again, a bewildering variety of steering combinations. Weighing only 150 kgs/330 lbs in sailing trim, U was quick, but was never developed anywhere near it’s potential as I kept experimenting with different ideas. U suffered from 3 different rigs, 3 beam arrangements, 2 windward hulls and a chopped down leeward hull, none of which were ever seriously optimised.
Both the 5m prototype and U used a ballestron rig. This is a rig where the boom is extended forward of the mast and has the jib tacked to it’s forward end and sheeted to a track just in front of the mast (see photos). The forces of the jib and the main balance each other out, resulting in a rig whose angle of incidence is adjusted by one lightly loaded sheet. Known as the AeroRig in the UK and USA and the EasyRig in Australasia, this rig is excellent for any boat, but for a proa is the difference between a 2 minute shunt with lots of hard work and an almost effortless 10 second one.
The steering/leeway reduction conundrum was far harder to solve, but eventually simplicity prevailed, and two balanced rudders were used, of a size which eliminated the need for centreboards. They have very low steering loads, and can be used individually or together.
These boats were both Pacific proas, and sailing them required a fair bit of body movement to keep the windward hull just airborne for maximum speed. This was obviously not the answer for a cruising proa. But then, nor was an Atlantic proa with a highly loaded rig and beams the answer for a lightweight, cheap, easily built boat. The solution had to be to combine the two, by placing the rigs and rudders in the lee hull, and the accommodation in the windward one. The masts could then be stayed to the ends of the beams, thus reducing the bending loads in both, the lee hull could be as long, low and narrow as possible, and the windward hull could be, within limits, whatever size and shape was required to fit the accommodation. Thus evolved the Harry proa, after a lot of sometimes heated discussion with traditional proa aficionados who wanted nothing to do with boats which were ballasted to windward by anything other than crew.
This perfectly logical solution was undoubtedly thought of by many people, but never tried, mainly because of a conviction that the added weight in the windward hull would cause the boat to luff head to wind as soon as it started to move. This has not happened, a trait I attribute to the 2 large rudders, the hull shapes and the balanced rig. Even under main alone, all my boats have been able to shunt and sail successfully.
To test the theory, I built Harry, a 12mx 6.5m proa with full standing headroom, 2 double bunks, galley and toilet in the windward hull, rig and rudders in the leeward one. Built of bending ply * and epoxy/glass, Harry was an incredibly easy boat to build and sail. I could shunt single handed in 8 seconds. It was also fast, easily achieving wind speed, despite, once again, never being optimised. Harry was another experiment, on which I tried various rigs, hulls, beams and rudders. Despite only weighing 650 kgs, it was incredibly tough, withstanding being blown off 500mm high blocks in the boatyard, and later being washed up onto a beach by waves ‘too big to launch a dinghy through’ and pounded for three hours.
Just after I modified Harry to try a single beam layout, we moved to Perth and a trailerable version became necessary to sail in the river and the ocean. Harrigami (Harry + origami) was designed as a folding, trailerable proa with accommodation for up to 4 people for weekend cruising and racing, with the potential to race offshore. It also had to be very cheap and, due to my rudimentary building skills, easy to build.
Mark Stevens and I drew a 15m/50′ harry for Australian, Dutch and Finnish clients. This boat was named Visionarry, for the Dutch boat which was designed to take blind people sailing. These boats were all strip planked timber and had very curvaceous shapes. They required a huge amount of filling, sanding and fairing.
In 2005, we were looking for a better way and hosted 2 KSS workshops with Derek Kelsall. These were a real eye opener about what could be done with foam infused on a flat table. I built a couple of hulls using this method and further developed it to use cheap flat panels moulds which cut the work required and the weight of secondary laminating for joins, fit out, etc.
One of the first clients to use this technique was Steinar Alvestad, a Norwegian building an 20m/65′ harry. Turns out Steinar is a stylist of some repute, so I employed him to redraw all the boats using the new methods.
Why a Harry proa?
Quite simply, proas are the best possible boats for their speed, weight, cost, building time or accommodation. For example Harrigami in sailing trim weighs 550 kgs/1,210 lbs, contains $20,000 worth of materials, was built in a leisurely 450 hours and has room for comfortable weekend cruising with reasonable amenities. Time and cost details are in the accompanying spreadsheets. With 31 sq m/334 sq’ of sail, it easily achieves wind speed up to 16 knots of breeze, despite less than perfect sails, which have been recut numerous times for the various rigs.
Harry proas have the minimum possible amount of structure. Cats and tris both tack. Therefore they see loads from both directions, and have to be built to withstand these. On any given tack, both are carting around a lot of extra boat, solely so that, on the other tack, they will work. Eliminating all the extra bits of boat results in a substantial weight loss. This means that a proa can have a far smaller rig for a given power to weight ratio, which further reduces the loads.