catamaran vs rib

[hilux38]

Hi everyone,

Which is a safer boat catamaran or an rib? if they were a similar size of course. I've heard so much about how great catamarans are, but never heard any of the disadvantages. Apart from the fact that you really need two engines powering a cat.

Do cats tend broach more if going down the face of a large wave? is their ride more unpredictable with a beam on sea?

I would like to know more about the characteristics of the catamaran hull, as far as ride-ability goes?

can anyone help?

cheers,

from the land of West Oz

[Jeff D.]

I run a 24' aluminum power cat with twin 150 hp outboards in the Gulf of Mexico, mostly in the area between Gulf Shores, Alabama and Pensacola, Florida. So bear in mind that my experience is with a somewhat choppier surf of a generally shorter period than might generally be expected off either the East or West coast.

The cat is the equal of a monohull 30% to 50% longer in a head sea. One notable advantage is that even a planing cat hull (which mine is) doesn't have the pronounced "hump" when coming up on plane. I can run fairly easily in the 12-16 knot range that is difficult for many planing monohulls, which means I can better match my speed to the sea state. The cat will sometimes "sneeze" if you stuff the nose directly into a steep oncoming wave, but this is easily avoided by tacking just 5-10° away from dead into the waves.

Substantially more care is required when running with the sea off the aft quarter. As the cat slides down the forward face of a wave (especially if the course is 30-50° off the direction of wave travel), then the bow of one hull will hit the wave trough before the other bow, causing the cat to "yaw" sideways a bit and heel unsettlingly to the side. I don't believe that I've ever really come close to broaching, but the movement is a little scary.

Hope this helps,

Jeff D.

[hilux38]

thank you for your views Jeff, are there any other opinions out there?

[jasipati]

Building myself a 24' powercat, I'm also very interested !

Jean-Sebastien
http://www.geocities.com/wildcat_sport/
jasipati