The unique design of a proa offers a couple of benefits compared to catamarans, trimarans or even monohulls, which made us choosing it for the proasis project:
- Proas are lighter than cats or tris and very much lighter than a monohull. Less weight means higher speeds are achivable due to less drag. A lighter boat can carry a smaller sail, which reduces the loads. Therefore everything can be built even lighter and more weight is safed. Due to higher speeds by low weight ocean passages are shorter and less food and water needs to be carried around – again, more weigth is safed, loads reduced and so on. Less weight means also less material to buy and work with when it comes to construction. In the end everything becomes smaller, lighter and cheaper.
- Proas are faster due to lower weight and reduction to the minimum (see bullet above). A faster boat is a safer boat: If heavy weather or a big commercial vessel approaches a fast multihull is able to avoid contact by sailing away. A slow monohull can’t and needs to face the storm.
- Proas are cheaper and faster to build compared to other designs. Less material and structural parts are involved.
- Each hull has a specific task and is designed accordingly. The lee hull supports the sail and is long and sleek to provide speed and pitch resistance. The windward hull doesen’t face big loads and needs no structure to support rigs, daggerboards and rudders. It can be much smaller and lighter with much interior space for its size
- The windward hull always faces the weather. By shifting the cockpit over there the crew gets a sheltered helm with 360° view.*
- No engines are required due the low weight. Our proasis proa will be light enougth to be human powered for docking manouvers.*
- Very shallow draft, no keel or unretractable appandages.*
- No extra sail, one size does it all.*
- Comfortable motion in swell. Proas pitch far less than cats as the rockerless hulls have very high prismatic coefficients. Sailing upwind, the bows of the hulls tend to meet the waves at the same time. This results in a monohull like motion (without the heeling!) rather than the corkscrewing motion typical of a catamaran.
- Additional weight doesn’t affect the sailing characteristics very much if stored properly in the leeward hull.
Bullets marked with * are not valid for all proas
Unfortunately there’s a rule in our universe: no benefits without a tradeoff!
Of course there are down sides on the proa design, too:
- Like all multihulls proas can capsize (allthough some designs like Tim Mann’s proa are hard to capsize) and are not self righting. If capsized they keep floating upside down and provide shelter for the crew waiting for outside assistance (see Burkhard Pieskes “Ana Varu” adventure)
- Shunting is slower than tacking and requires more space (proas are not made for narrow waters)
- The overall dimensions of a proa for the same interior space and capacity as a catamaran or a monohull are bigger
- The fore-aft symmetry is a challenge for the rudder/daggerboard design and the balance of the vessel
Nethertheless, for us a proa is the way to go. There is no other design which is as simplistic, cheap, functional and rapid to build as the proa. And after all, that’s what proasis is all about.