[PSUBS-MAILIST] ABS hatch rules and alvin

[Lucas Gray <lgray@tera.engr.mun.ca>]

I've heard and read that the ABS hatch rules are require about 2 feet,
from the hatch to the water line. The alvin submersibe does not appear to
have this but instead has a free flooding (fiberglass?) conning tower that
appears to have flood holes below the waterline. I assume that these holes
are oneway valves such that after the water drains out a passing wave will
not let water come back in. so the pressure hull hatch is at the water
line but the entrance hatch is 3? feet above the waterline... does this
simple modification satisfy the ABS rules..? if not, is the alvin
insured? by who?

lucas