Chrisj
chrisj wrote:
kayakman, I'm not claiming personal expertise in this area, but looking around a few sailing forums, the relative importance of rig vs hull in pointing ability seems to be hotly debated, with the most common consensus being that they are about equally important.
I found a few comments that Bermuda rigged boats have a slight edge upwind, but couldn't find any statement that the difference was as much as 30° vs 45°-50°. Do you have a link to that?
I used your numbers from a from a previous post, but they seem fairly close in my experience. In optimal conditions, I think 35 is reasonable, 40 in less optimal conditions, and 45-50 over 25-30 knots of wind.
chrisj wrote:
The superior upwind performance of Bermuda rigs seems to be attributed to the triangular shape of the mainsail being less prone to twist than the four sided cat rigged sail. In that respect, fusioneng's setup isn't really a Bermuda rig, since it lacks a triangular mainsail (and likewise the Hobie Wave).
From my research, it's the jib that is the big upwind engine. The mainsail is relatively inefficient upwind. So any boat with a jib should point further upwind and at greater speed than one without. I don't have a jib or a bermuda rig so I don't know these things by personal experience.
chrisj wrote:
Couldn't your inability to keep up with the other boats in the regatta going upwind be due to you being the only trimaran, so more prone to leeway than the other boats?
Two trimarans flew past me, one came from way back in the pack. Both had bermuda rigs. So no, I don't think the number of hulls has much to do with leeway. Hull design certainly can affect leeway but I think Hobie has done a very good job with the TI hull. I have forgotten to lower the centerboard on occasion and found it does okay without.
chrisj wrote:
Incidentally, do you think a TI being sailed solo from the rear should be thought of as a full displacement or a semi-displacement hull? I'm sure you would have seen Eduardo Cavendish's clip of him sailing close hauled from the rear seat:
I don't know if you'd call it planing, but his bow is mostly up out of the water.
I would call it planning, I've topped out at 13.3mph. With a minimal load and enough wind the TI will plane, however that doesn't mean it's planning hull or even semi-displacement. It is very much a full displacement hull. It does have a large flat bottom that can act as a planning surface, but with a full load the hull design limits the speed to five or six knots.
j