: Thanks for your feedback. I'm was thinking of going with screws as well but
: here's my concern. The rim flange is only about 1/8" thick. Does not
: leave much meat to countersink the screw heads. Also, if I install them in
: the middle of the flange, they'll be under the hatch cover and the screw
: heads may interfer with the hatch seal.

Didn't realize the tolerances were so tight. Are these the KajakSport hatches? Under the circumstances, adhesive may be your best shot. If these act at all like VCP hatches, the most significant waterproofness will derive from the walls of the hatch cover mating to the upright flange, so not having a tight seal at the horizontal surface may not be a very big deal --- but, with these, that may not be the case.

Yes, my concern with adhesive mounting is that it's a bear to get off if you want or need to replace the fitting in the future. I'd be less concerned with maintaining a good seal, unless you're working with a cambered deck; you really need to have a pretty flat surface to mount these things properly.

Another thought --- from experience: if you have to sit on your after deck to get into your boat, or even if you have to hold yourself up by grasping the chines to slide in (I'm also a Pintail driver, with a 16" by 20" cockpit), consider carefully where you install a day hatch. You don't want to place it where you --- or someone using your boat --- would naturally rest your hands while getting in or out. These things make lousy handholds! (Again, from negative personal experiences.)

Good luck with the install. Would like to hear how it comes out.

Jack

I still like