Retractable rudders allow for minimum draft and provide nothing to act as a lever to flip the boat. A 15m x 8m raft drawing 150mm/6" is a very stable platform. However, flipping multihulls under bare poles is pretty unusual. The other advantage is that you can run the boat up the beach and step off in shallow water past the breakers rather than in them.
Flat or round bottoms would not make much difference.
If the boat was very light, and/or had a wing mast and/or a solid bridge deck, then water ballast may be helpful.
There will always be a wave that is higher than the beams, but if there is adequate deck drainage, it would not be a problem. Running with a drogue, it would be pretty unusual to have a wave break on the deck.
The musts are a drogue and a sea anchor if it gets really gnarly or you are on a lee shore etc. Most important is good preparation (seems to have been missing on the Alpha), a boat that does not tire the crew out and as few things as possible to break or go wrong, and what there is to be suitably strong and well tested (seems the Alpha failed these as well).
rob
On Fri, Jan 17, 2014 at 5:47 AM, <lucjdekeyser@telenet.be> wrote:
A newly built Alpha 42 catamaran was abandoned a couple of days ago in heavy seas. It had broken both rudders and was leaking apparently. The truth or the details are not important for this thread. It serves here as a reminder for cruisers to take such conditions very seriously.
What is the safest HP design in these conditions? I would venture this design would feature round bottom hulls and retractable rudders & boards. Would water balast be a factor in general? Clearance of the beam? What would be musts and what just nice to have?Thank you.Luc
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