7 years ago I put flush hatches on a Panache I built. No straps of any kind. I used a small hole in the center of the hatch with a pece of threaded rod going through the hole which goes into a cross member (dowl stock 1/2") under the deck. You tighten the knob on top of the hatch and it cranks it down towards the cross member below the deck. To remove the hatch you simply slide loosten the rod (unscrew it a bit) and slide the hatch off.
I previewed this for Nick who is usually in disbleaf and the kayak actually hissed out air as it was loostened. It is absouletly water tight and easy to make. Eric Shade incorporates it into all his boats now. Someday Nick will also.

If you want a drawing, email me your address and I'll send out something.
Others on this board have used it and may have a photo to post.I'm not looking for credit for the world's greatest kayak invention.
jbabina@snet.net.