wrote:
DSK wrote (in another thread):
Actually, I think it would be a good project to add positive
flotation to any cruising boat that ventures out into big water.
Some care should be taken with the volume distribution , so that
stability is mainatained, as well as ensuring sufficient volume.
You could utilize the interior angles & odd nooks so as to not
lose too much stowage.

How do I figure out how many cubic feet of foam I need to add
to a 46' Tayana Pilot without filling it with water ?

Hull: Fiberglass
Displacement: 34,500 lbs
Ballast: 11,000 lbs

For more details see http://www.tayanayachts.com.tw/V460.htm
and http://tayana46.tripod.com

It has a watertight bulkhead in the bow and a large storeroom
(lazarette) in the stern. Do you think it would be enough to just
put the floatation blocks in these areas ?

Their is a company that makes side rails that are inflatable. Not so
sure how good they are, lots of people die in accidents on boats with
flotation, most roll over when filled with water and acted upon by
waves. If your that concerned maintain the boat properly, you can set
the engine(s) up with crash valves, carry good insurance and invest in
a raft. Things happen when your on the water, being prepared is the
most important thing to be.