Hawaiian Sailing Canoe Rig

I've been on the Holopuni site many times, admiring their OC3 sailing canoes. These 30' canoes are wonderful examples of efficient paddle/sail craft, but still, I can't help meddle with an already good thing.

See, I'm anticipating the next step in sail area/performance upgrades. The Holopuni carries just 100 sq. ft. of sail, which is no doubt plenty for Hawaiian waters, and it is a safe and sane amount for a dual-purpose sail/paddle craft. But what about unsafe and insane sailing?

Unlike most Hawaiian sailing canoes, Holopuni prefer to rig their canoes as true double outriggers (trimarans). If Holopuni were a typical trimaran, they would just step a taller rig to increase performance. But more sail area would create more overturning force, and the short 14' amas would bury or pitchpole just as the fun was starting. So bigger amas would be specified, and then bigger sails to push the heavier boat, and then bigger amas still, until finally you get to this:

While undoubtably fast under sail, Fuji Film doesn't paddle well. And that's the challenge - how to improve sailing performance without degrading paddling. The solution is to refuse to think of the boat as a trimaran, but always as an outrigger. Sail the canoe like a Pacific proa, heeled to windward, not a trimaran heeled to leeward. Keep the windward outrigger down, and the leeward outrigger flying.

How? By pulling the foot of the sail over to the leeward ama (with block and tackle), to give the rig a windward cant. The canted rig creates upward lift to counteract heeling moment, so the canoe will show considerably less overturning moment than a conventionally rigged canoe of equal sail area. The boat will be faster because:

• It's sailing on its long center hull, not its short ama -- less wave drag.
• The canting rig reduces negative lift of the conventional rig, so the hull rides higher in the water -- less drag.
• The amas can be much shorter and lighter than a typical tri -- again, less drag.

I've shown the boat with 150 sq. ft. of sail. 50% more than the Holopuni standard, but still conservative. The canoe will still paddle well. In light airs the sail foot would be pulled to the centerline to keep the rig vertical. Holopuni rig their canoes with a free-standing carbon mast, and that would be a good thing to continue with the canted rig, because side stays might interfere with the sail when in the canted position.

Downside? I've seen some canted rig boats sail, and lets just say that the crew really needs to be alert. Unlike normal boats, the overturning force INCREASES as the boat heels, because the sail becomes more vertical and presents more sail area to the wind. The result can be some spectacular high-speed crashes if the crew isn't really quick with the sheet. But no guts, no glory. It would be an amazing ride while it lasted.

Comments

• Cool idea.  I’m working the Gary Dierking angle with a 21’ Ulua huled tri.  It’s got a 128 square foot sprit boomed leg o mutton with lots of roach and four battens--two of them are full length.  It’s got a reef piont that takes about 4’ out of the bottom of the sail and tramps on each side that measure 4’3"x10’8".  I still need to figure out if I’m going to deck the thing a la Holopuni or use a huge spray skirt like the hawaiian canoes in HRCA.  The only thing I don’t like so far is that the mast was built too heavy and that makes stepping it solo a challenge.  Instead of the canting rig perhaps just a big beachcat rig with a way to furl the jib and reef the main?

  Posted by  on  08/24  at  01:37 PM

• the tri is an inherently inferior design that preceded the catamaran - forget it. as you’ve pointed out yourself, more sail means bigger ama. eventually you get rid of the centre hull and are left with two large ama - a catamaran.

  the proa was replacing the catamaran as a superior craft in the Pacific when Europeans arrived . don’t go backwards to the tri.

  Posted by  on  07/13  at  03:08 AM

• Ron,

  How well do cats paddle?  Proas are cool, but not everyone wants to shunt.

  Dan

  Posted by  on  05/25  at  06:41 AM