Thanks guys...the plywood has no voids the glue is water proof ( I have had a test pc. of 1/2'' BB outside nailed to a fence post for a few yrs. with no delamination) 5x5 sheet of 1/8'' about $12 at my local cabinet hard wood suppler "Liberty hardwoods"....
I have done multi chine SOF's with Kayakfoundry which is pretty easy ,closer to the old way before computers......
This Baltic Birch is strong and more easier to work with than 4 mill. okoumie which is beautiful wood, but the price of marine ply. is outrageous here in Kansas City besides that they don't stock it......

All wired up and ready to fillet...It is always nice to have forms on a strong back to keep everything aligned when doing a S&G..