Since a wooden boat is encapsulated in glass and epoxy is it really necessary to use marine ply? Wouldn't regular ply be adequate?
Thanks

I've found that marine ply is higher quality - no voids, and better quality wood in the interior laminations, and a bit thicker face plys than the equivalent 'regular' plywood. So, if you are putting a lot of work and $$ into a project anyway, I think that marine plywood is worth the extra expense.

Having said all that, I have made a couple of 'quick and dirty' S&G (boat) projects using very cheap 'doorskin' plywood and they held together OK. I was painting those, so the cosmetic defects in the cheap plywood weren't a problem.