Okoume is very flexible and needs to be encapsulated. It is used by the Outer Banks
boatbuilders when they need to produce the pronounced "Carolina flare" hulls. Sepale and Maranti tropical wood marine
plywood is very durable. Some builders in NC still use Douglas fir as it bends.
Pine is a soft, knotty wood. Not good.
I spoke with Scott Roberts of Roberts Plywood (a large northeast supplier to boat builders) regarding the glue issue. He said it is like answering "is there a difference between car brand quality or the quality of different producers of chicken? Would a good quality marine
plywood use the same glue as a bad quality exterior plywood, no."
The tropical woods have less knots and a tighter grain. There are fewer voids, repairs
, plugs, defects and patches in the plywood.
gets in a void and the temperature changes the trapped water
expands and delaminates the plywood plies. The glue helps keep the plies from delaminating.
He said to look for the British stamp 1088 to be pretty sure you are getting good quality marine plywood with few voids, lots of plies of the same species without lots of interior repairs
Also regarding the glue, a lot of plywood comes from China
. And you know how reliable they are about quality. They even falsely stamped a bunch of old flooring
as being low formaldehyde and sent it to Lumber
Liquidators- and they are now being sued.