catamaran bows

[rlawler]

I think the biggest problem with catamarans is their propensity to pitch-pole, where one of the two bows gets buried in a wave and the wind acting on the sail plus the boat's own momentum then makes it flip over. It seems like everyone already knows this and yet I have never seen a catamaran design where the bows were deliberately designed/shaped to ride up over a wave. The bows always seem to have the same shape as a monohull--straight down or sometimes very slightly raked back. Monohulls with their heavy keels obviously can afford to have a bow like that because they are not going to flip "head over heels". But it seems to me that catamarans, being susceptible to this problem, can't afford to have a bow like that just to make them look more traditional--to make them visually similar to a monohull. Sea kayaks generally have an upswept, high volume bow for the very purpose of making them ride up over oncoming waves. This type of bow is precisely what a catamaran needs in heavy conditions. Yet I have never seen a cruising catamaran designed with bows like that. Would it not work for some reason?

[Figment]

Sooner or later you're going to encounter a wave taller than the bow can override. A big flared-bow makes the pitchpole worse, not better, as the submerged hull is slower to return to the surface. Modern cat design goes the other way... needle-sharp "wave piercing" bows that offer minimum resistance to the wave and are able to regain the surface with little effort. They look upside-down in section, like an elongated teardrop shape, fat at the bottom and peaked at the top.

[Woxbox]

These don't go over. Wharram builds in lots of reserve bouyancy. And draws a conservative sail plan.

http://www.castawaycats.net/images/sail1.jpg

[JimConlin]

http://www.morrellimelvin.com/playstation/art/PlaystationJumping.jpg

[George Ray]

http://www.teamadventure.org/images/mainpages/indexbottom.jpg

[mmd]

The perception that cruising catamarans are highly susceptible to pitchpoling is highly misplaced. Yes, pitchpoling is a concern with Hobiecats and extreme racing multi's, but as common in cruising cats as roll-overs are with monohulls. Presuming that cruising cats are as likely to pitchpole as racing cats is like saying that your family sedan is prone to crashing because you saw the same model car crash week after week on NASCAR.

Cruising cats are more likely to lose their rig in a bow-stuff than to pitchpole. The rig isn't strong enough and the hull isn't light enough to allow it to go over. Proper engineering makes it so.