: How dumb would it be to do recessed hatches on a SOF?

chip, you’re finally getting it!!!
but you have company too with all these other guys responding. not me.

anyway a little difficult with some of those lowback greenland decks

i like your approach of flush flat framing from stringer to stringer that responds to the sectional shape. then the flowing lines of the yak/stringers are retained. i think the round and flat coaming type holes just don’t fit. dogs breakfast.

so say you framed stringer to stringer with tiny dishout betw(to give slight shape), and tied down under the bottom face of all. urethane coat, then build(possibly anchor bolts so all can remove) a flange under just like we do with strippers or s&g. build a corresponding(to the yak stringers) stringered/framed hatch and skin that. seal and mask it into some silicone on the flange below. now all the idiosyncracies of the framed hatch will be echoed in the silicone for a good seal.
for latching, maybe a whole series of web loops around from the flange up. and corresponding between for the lid.
then just alternatingly ‘sew’ on with a bungee or more traditional line. or could go over to the adjacent gunwales.

shawns idea of the use of strip magnets in flaps of fabric sounds great. might be the best use of all as the fabric can deflect. could have flap all around the lid and magnets under the fabric past the opening. (or as usual in the flange.)

:Same concept with the bulkheads.

bulkheads would be more tricky.

simplest is the seasock from ea hatch.

or as each stringer and gunwale passes thru the bulkhd, could cut a clothskin one but say 5” wider than the shape all around. choose location, urethane goop for 3-4” all under each stringer/gunwale filleting out to the skin then placin the cloth over with the 5” flap overlapping the urethaned sections, baste in place and seal up with the polyurethane paint. depending on seal, remove basting – maybe keep lashed to nearbye rib.

other approach would be to seal the wood in the b/h region, use a sealed wide rib w/ one face aligned w/ one face of a deck beam, small block on i/s of ea gunwale to continue this face. spray foam betw rib and skin around stringers, deckbeam to skin also. attach 3” oversized skin b/h to this flush side, glue or paint oversize flap all around. maybe sealant or glue (below) on face of the foam.
(polyurethane glue sure bubbles up w/ lots of water, wonder if could use that instead betw. or at least one side of the foam)
real issue would be difficulty in drying frame out betw use. lots of water trappers.

-mick