Dan-
There's no simple way to build a raised coaming in the older hatch system, as the top of the lid is flush with the deck level, and the the bottom of the lid and the seals are below that in a depressed cutout with the seals mounted to the lip at the edges. Best way to deal with it would be to
1. install catches that hold the lid tightly against the seal,
2. don't open the lid very much, and
3. put stuff below the hatch that isn't water sensitive.
My port lazarette is set up as a live / bait well which has it's own drain, so no water problem there; and the starboard one has one of the batteries in it with the battery switch and other electrical equipment for the trolling motor, all of which is pretty well shielded and hasn't yet given me any problems with fresh water passing down through it in moderate quantities, but for salt water, I think I'd better install a catch that will hold it tightly shut.
Nice idea on the urethane adhesive! Joe.
