you could use a cyanoacrylate (superglue or krazyglue) to hold them together, or a 2 part epoxy. They also make an excelerator for these glues so it is pretty much instantly cured after you spray it on. You would just have to make sure that it is waterproof after it has cured. There is an epoxy that cures underwater used for surfboards. just look up epoxy glue on wikipedia and there is an explanation and picture on the right hand side of the screen.