Hatch gaskets take a little extra care, no question about it. I've certainly gone 'round and 'round with 'em (and own two OI's too). Here's what I know.....

If you don't like the selection of weatherstrip in your local hardware store, shop around. It's well worth taking the time to do. Pick what looks "rightest", and try it; if it fails to perform to your satisfaction, yank it out and try something else. The stuff is cheap and important enough a detail to belabor, and your experiments will be good for every boat thereafter.

If you have leaks, increasing hold-down pressure is the wrong solution, and will lead to other problems. Ask me how I know. Necessary hold-down pressure is surprisingly light.

The tiniest irregularities can cause astonishing amounts of leakage. See to it that hatch gasket surfaces are smooth, with no bumps or dips. Attention to detail is never more worthwhile than right here. Fill coats and sand paper -- use 'em painstakingly.

Ask Tony how to make a counter seal on your hatch lid if you want to tighten up the seal on an existing hatch. I have learned that it pays dividends to build very carefully around hatches, but if it's too late for that, his silicone caulk counter seals can really help.

I like the Leidy internal bungee arrangement on flush hatches, using the One-Ocean method for laying up fiberglass/carbon fiber/kevlar/whatever gasket channels. I came within an ace of installing NDK/VCP style rubba bubba hatches and rims on my latest effort, but finally decided to abort because they're too heavy/too expensive/too ugly as compared to the genuine homespun article. Performance of the flush hatch can be very as nearly as good as long as pains are taken to remember that ANY water-tight seal requires extra care and deliberation in manufacture and use, no matter what application.

Finally, ALL hatches are subject to leak at least a little dribbling bit. If you get one that reliably renders a bone-dry compartment, thank your lucky stars for the charmed life you live.

My web pages: http://mysite.verizon.net/NGC704/newOI/Page_7.htm