: I agree, if choosing between those 2 alternatives.
: Epoxy paint can be pricey- 'real' epoxy resin might not be much
: more expensive, and the 'leftovers' can be very useful.
: If there are any voids in the plywood, they can cause a problem.
: Seal/fill the edge voids at a minimum, I think.
: I used 'birch plywood' (the big-box, non-'Baltic' type) once on a
: speaker project. Never again......

If you use regular epoxy remember it is susceptible to UV and should be protected with good quality exterior paint or varnish.

Unless your SOF boat is going to stay in the water for long periods or be stored outside in all weathers, it is OK to simply paint or varnish the ply, expecially if it is good quality baltic birch: take extra care over the edges.