Jeff wrote:
...
If it was designed into the boat, it would be 13 cu ft per foot,
or about 3 inches thick around the hull and deck. This would
also add a lot of stiffness, insulation, collision protection, etc.
However, if you were doing it from scratch, you'd probably
pick a much lighter design - the Etap 46 is 27000 lbs while
the Tayana is actually 42000.

Maybe it's easier to make a MacGregor seaworthy than to make
a Tayana unsinkable :-)