if building a boat that does not have hatches e.g front deck of a pax 20, is a breather tube or a scew plug required for air expansion? I live in a hot climate and have been paddling surfskis for a number of years now, they have all had a plug that is left open when not in the water. hollow surfboards and the kaholo all require some way of allowing hot air to escape. The seams of a surfski are far less substantial than the px 20 woith its shear clamps, so perhaps the increased pressure from hot air inside isn't such an issue. Thoughts anybody?