Bruce,

I went with a knob-closed hatch like the one you can see in the upper part of this picture. The think I like is that they provide a good, solid, mechanical clamping force. I haven't got a single drop of water in my hatches, and my Outer Island is low-volume, so those hatches get covered with water pretty frequently in a chop. There are 2 ways to do it, that I know of. In both cases you epoxy a threaded rod (a stainless bolt with the head cut off) to the knob. Put the rod thru a few thin rubber discs (i.e. bike inner tube) to keep the knob from leaking, and put it thru the hatch lid. On the other side you screw it to a dowel or bar that has a wingnut epoxied into it.

Jay Babina uses a dowel that runs along the length of the kayak and is about 2" longer than the hatch -- visualize it running down the center white stripe in the picture, 1" longer than the hatch on either side. To use it you have to 'scoop' the hatch foreward, drop the back of the bar all the way down, then slide it back and tighten it down. If you put some little foam blocks to guide it in on either side of the dowel on the underside of the deck, it makes life easier.

Eric Schade uses a slightly different method, I think. His draw-bar is just slighly shorter than the length of the hatch, but longer than the width. You install the hatch with the bar running length-wise, and when you turn the knob, the rod turns 90-degrees, hits stops mounted on the underside of the deck, and draws the lid tight.

I built my hatches to Jay's method, but might be converting to Eric's method. I have a problem with the hatch sticking to the gasket -- it takes a lot of prying to get the edge to break loose, and I can't just pull up on the knob because the draw-bar won't fit vertically through the opening.

I made a slight modification to Jay's plans and instead of a dowel, I used a piece of U-shaped aluminum channel with a wingnut wedged into the center. I applied Plast-I-Dip (made for coating tool handles) on the tips to avoid scratching the deck.

Dean