BOAT wrote:Why do they make sailboats really beam-y now? What is the purpose of that? In the old days (well the 70's) they were narrow but nowadays it seems all the boats are getting fatter and fatter? Why is that?
Is there an advantage to that I am not aware of?
The primary advantage is that it more readily gets permission from Admirals to purchase because it's homey. Narrowness makes even a perfectly adequate space feel very small. Actual submarines have this problem, and the Navy has to do psych evals on prospective submariners to determine whether or not they will be able to deal with it long term. 90% of the time spent on boats these days is at the marina. They're often little more than floating condos, and the boat makers have realized that. Thankfully we have ocean ratings and ratios to keep the evolutionary forces of luxury in check.
That said, there is a newly discovered racing advantage to a beamy hull shape. If you look at the pictures of my boat sailing in 25 knots, you'll see that 50% of the _bottom_ of the boat is out of the water. The boat is actually acting like a catamaran with an ama out of the water. This is why the boat has to have twin canted rudders.
If you look at the chine on this boat, it's as if someone took two planing boat hulls, rotated them 30 degrees, and welded them together. The chines are actually designed to be the bottom planing surface. So what you get are two planing hulls, one for each tack, each with a canted keel pointing to windward, with the windward hull entirely out of the water. This is extremely efficient for sailing as 50% of the wetted surface gets out of the water on a heel--similar to how Macs have reduced wetted surface at a 15 degree heel, but even more extreme.
You can think of it as a semi-catamaran in that mode, but with the stability of a keel and the AVS of a monohull. It's a balance designed to be the best of both worlds.
This boat readily exceeds its theoretical 8 knot hull speed without a pause and goes straight to 9 knots on a semi-plane, able to reach 10 knots--and that's on a reach, not downwind. You can feel a strong acceleration when it gets up on the chine and the wetted area reduces.
The boat is also stable on its chine: It heels first to just a few degrees, then suddenly to the chine, then stays there without rolling. Form stability resists movement away from the chine once its on it, making the boat stiff between surfaces. Its very comfortable.
The problem with it in a storm is that like a catamaran, it's going to move atop the waves rather than rolling with them. On the plus side, it surfs, which makes it less likely to be rolled in a broach than a round full keel boat, but on the minus side, I expect it will be very uncomfortable lying ahull in a storm.
Matt
