: The subject of venting sealed compartments has been discussed on this forum
: before, but, with hot weather here in in earnest for a lot of us, it bears
: repeating.

: A hot, black hull soaks up a lot of heat on the beach at the put-in, and
: especially for boats without hatches, the strain on the hull when the
: kayak is put into significantly cooler water can be impressive --- and
: serious --- if the decrease in pressure as that hot, expanded air in your
: forward and aft compartments cools and contracts. (This is most
: significant for boats without hatches but with inspection ports in the
: bulkheads.) A compartment, if not allowed to vent to atmospheric pressure,
: can literally implode, opening up a small, fractured surface in the deck
: or hull --- nature finds the weakest section after a while. It's bad if
: it's the deck --- a lot worse if it's the bottom and you're a half mile
: offshore when the atmosphere abhors the vacuum enough to equalize it for
: you.

: To keep this from happening, drill a small hole in the bulkhead, fill it with
: epoxy, let it cure, and then drill out a very small hole --- it doesn't
: take a lot to vent a compartment, and a 1/64" inch bit isn't too
: small --- as close to the center of the bulkhead's surface area as you can
: find. (Technicially, it's the metacenter, but that doesn't mattter much.)

: I've only experienced a hull failure once, but it reminded me what
: atmospheric pressure can do to a boat when a compartment is very well
: sealed.

How about a nice little check valve. One that allows air out but no water in.

Pete czerpak albany, NY