Need a couple of dimensions. On the coaming:
How much space/height under the lip?
And how much lip? How much should it extend out?

Now on the hatches. Any recommendation on weatherstripping? I know I have read this before but I can't remember what was suggested.

Last question. I have decided to go with the straps and buckles to hold the hatches in place. I don't want to do a screw and washer on the deck. So I am thinking about doing something like the soft pad eyes on the ends. Unless someone has a better idea .... and I wouldn't be surprised.