Weatherstripping is the quick-and-easy way. I went with 3/8" wide x 3/16" thick from Menards -- 3/4" wide would have been too tough to compress. Some people go with pure silicone. They put a mold release (PVA is supposedly the best) on the lid or cover it with plastic wrap, put a generous bead of silicone on the lip, squish it in place, and tape it flush with the deck. Do a search and you will probably find a string of posts going into more detail on this.

Dean

: I cut some flush hatches in my Expedition Single and built up fiberglass for
: the lip per Nick's book. I thought I had inset the hatch lid deep enough
: to leave some room for the gasket so it would be flush with the deck. It
: is now close to flush without the gasket(maybe 1/16"low). Any advice
: on gasket material that will just slightly raise the lid ? I thought I
: would use self adhesive foam weatherstripping, but am now wondering if
: caulk would be a better material. If so, what is a good procedure for
: caulking the lid. I'm so close to being in the water I can taste it.
: Thanks