Posted: Jul 25, 2012 - 01:48 PM
Don't worry if some of the ideas of cat sailing take a while to wrap your head around. That's true for other cat sailors as well. When my boat (a Pacific Catamaran) was first designed, people DID sail directly downwind in catamarans. Rick White mentions this in his Catamaran Racing / Sailing for the 90's book that was already mentioned. It took someone trying that trick of sailing 45 degrees off of downwind on a reach to demonstrate that even though you're covering more ground, you're covering it so much faster that you still beat boats going wing-in-wing downwind.
Similar story (also mentioned in that book): Conventional wisdom has it that a cat's most efficient atittude is to be up on one hull, with the windward hull just baaaaarely kissing the water. For upwind sailing, all the hiking and getting out on a trapeze wire is specifically to get your boat into that attitude. Downwind? Well, that's just a slower point of sail, right? Turns out the answer isn't so simple. Randy Smyth (if I remember right) decided to try hiking out on the leeward side of the boat on a downwind reach (again, 45 degrees off the wind) to raise his windward hull. It worked GREAT. He and his crew dubbed the maneuver "Wild Thing".
People still struggle with "Wild Thing", and not every racer will do it. You'll never run into the maneuver anywhere but on a catamaran or possibly a trimaran. Even other cat sailors may not have heard of it, or ever want to try it. But it's been demonstrated to work. Smoke and mirrors indeed.
I'll second what Bob said about suggesting Rick White's book. It's a treasure trove of information on cat sailing. I haven't put even half of it into practice yet.
Something else that I think was mentioned in another thread you started about sail flatness bears repeating: Some aspects of the sailing world are pretty static. Catamaran sailing isn't one of those. It's an incredibly dynamic field of development. When I started sailing catamarans, there were a handful of people who were cobbling bowsprits onto their cats so they could put up asymmetric spinnakers. Some people laughed. Other people's jaws were dropping when they saw those boats making twice windspeed on a beam reach. These days asymmetric spinnakers on racing cats is the norm. The one-design classes almost all have spinnakers.
Sails went through a revolution as well. You'll see this come up in discussions about pre-bend on masts, downhaul, and sail shape. With a mylar sail you can change the flatness of the sail with downhaul, but your mast has to be designed for this. The same trick won't work on a sail made of Dacron sailcloth. The headboard would rip out of the sail first.
Unfortunately things like this can make for all manner of confusion when reading about boat setup in a forum like this, or when looking at other people's boats at a regatta. Try to make a Dacron sail take the same shape as a modern mylar racing sail, and it just won't work. They really are different beasts. Unless you're looking at someone with the same boat using the same mast and the same sail, it's hard to make comparisons.
The good news is that unless you're into hard core competitive racing, you can take a lot of this with a grain of salt. Basic boat setup and good sailing technique will get you 95% of the way there. When people really start dropping money on a boat, it's to get those last few percent of speed out of it. For my money I'd rather spend more time out on the water learning to be a better sailor. More fun that way.
Rick White covers most of this in his book. It really is a good read.
Tom
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Tom Benedict
Island of Hawaii
P-Cat 18 / Sail# 361 / HA 7633 H / "Smilodon"
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