You are right that slamming can be a major problem and is certainly something that all designers consider when designing a bridgedeck cabinned catamaran
. Unfortunately life is a compromise, increase bridgedeck clearance and freeboard, windage and weight will go up while (generally) aesthetics goes down.
My general rule
of thumb is that you should be able to get a conventional inflatable dinghy
(ie not a RIB) under the bridgedeck, (although I'm not convinced about Aussiesuede's idea!) I would avoid boats that don't have that much clearance if you want to be comfortable offshore
I'd also avoid boats (like Prouts) with big nacelles as they, in my experience, slam more than boats without nacelles. I'd also avoid sleeping in the bow bunks of any catamaran
, the only good sea berths are aft of the mast
Incidentally I sailed the Capetown to Rio race
in a Norseman 43 (similar to the Voyage). Apart from stores for 6 men
for a month the boat was empty (no dinghy
for example) and it slammed very badly. Loaded for cruising it would be much worse.
thinking is to have a gently V'eed bridgdeck floor (as on my Transit 38 design). That way the wave energy can dissipate sideways rather than straight up.
What certainly works extremely well is a big hull
knuckle (again as on my Transit and also Eclipse and Sagitta designs) which deflects waves down and helps break the solid water
into spray. The fact that you get less spray on deck
and have more interior room is a bonus.
It maybe an unsurmountable problem, but as I said at the beginning, bridgedeck slamming is something that concerns all catamaran designers
Richard Woods of Woods Designs