Alan, what I was trying to say was that I'm thinking of gluing a thinner teak and holly veneer to a substrate (1/4" marine
ply?). (I may find that it comes that way, anyway, but I haven't checked lately.)
This would then sit on the existing marine ply subfloor.
Thanks to your comment, though, I'm now thinking of cutting this in sections, like a series of larger hatches, and fastening them in a way that would make it easy to get them up again. This will eliminate fiddling with small access cutouts and hatches over them, and provide unrestricted access to the bilges.
I have shallow bilges and great respect for Murphy, so I don't think I'll route
anything new where it might get wet, but this way, all the options (and the access) stay open.
Thanks, too, Gord re: clearing things out - I did notice some crud in one spot, and hadn't thought to check if it had blocked any channels.