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.

Jack Martin