Ben,
I think the difference is that we're discussing two different
types of safety and boat purpose.
The Weta is a brilliant design for daysailing and racing, with a
form factor that will work for the greatest number of people in
conditions where you would normally use and race a 4.4 meter
trimaran.
On a good day, with relatively flat water, and a non-expert
skipper, it makes perfect sense to submerge the lee ama before the
main hull files. You can't push the boat too far because it's
self-limiting, and you have great feedback as to how close you are
to "too far". In fact, even if you're a speed freak who doesn't
care about risk, you'll /still/ want to keep that ama from going
under.
An expert skipper could handle flying the main hull, but that's
dicey. The Reynolds 33 catamaran was banned from a number of races
because of several capsizes. Race committees decided they were
over-canvassed. Randy Reynolds argued that the boats were
over-canvassed only if sailed improperly. But since not everyone
owning one was as good a catamaran sailor as Randy, the race
committees had a point. I think some have let the R33 back in, but
the point still stands: if you want to maximize sales, you can't
plan on every skipper being expert.
So submerging the lee ama is a good idea for Weta to implement
from a design standpoint.
However, what's safe on a small boat on a good day is not
necessarily safe when out of sight of land on a bad day. If you're
out in a Weta, it's not likely that you'll be seeing 10 meter seas.
Or even 2 meter seas, for that matter.
On a cruising proa, there's a good chance that you'll eventually
encounter big winds and big waves at the same time. Submerging that
lee hull could then make for a very ugly day when powering through a
2 meter wave, or perhaps more likely, when surfing down a 10 meter
wave and hitting the trough. In these cases, a high-buoyancy
wave-piercing hull would be the safer bet.
imho, of course.
- Mike
bjarthur123 wrote:
perhaps it doesn't make sense on a harry or the two tris you mentioned, where there are foils in the lee hull. but on the weta you would lose control if the main hull flew because that's where the only rudder is.
it is a big safety feature in my mind then that the <100% floats on the weta make it impossible to fly the main hull. it makes it MORE forgiving, not less. check out this video:
http://www.youtube.com/watch?v=WKuDEs_9sB8
the alternative on a boat with leeward foils is that you fly the main hull and risk capsizing to the side. which is more likely, that, or more drag from submerging a <100% float causing a pitchpole forward? i'm not sure. just thinking out loud here.
drag from the beams can be minimized. imagine a schooner harryproa whose two beams attach directly to faired stub masts. load paths wouldn't go through the hull, and with a smaller volume to boot, would be lighter too, no?
ben