Hello African,
You should have gone for the marine ply instead, at double the price ! I would still advise you to do that. Marine ply has it's layers glued with a water proof glue, the standar ply's glue dissolves in water ! which means it will disintigrate in no time when it gets wet.
The second thing is polyester resin - which is the most economical to use, does not adhere and seal wood well. You have to use epoxy resin instead - again at more than double the price.
My advice is to do it the right way or you will have to do it again in a short while. That boat has a nice hull, all cathedral hulls are stable though choppy, but do it right and you will have lots of nice times fishing.