3M Marine Adhesive Sealant 10 oz.

Folks, if you have something that needs to be waterproof and almost permanently attached, this is the stuff! I worked for years in the boat business, and this is a "can't live without it" kind of product. It sets up and cures underwater and is immediately waterproof. The adhesiveness of this product can't be over-stated; don't stick it if you plan to move the item later. I've patched seats. convertible tops, and mounted thru-hull fittings WHILE IN THE WATER. It can be removed but it won't be easy. No, its not cheap but it does exactly what it says, and the peace of mind is well worth the price.