I purchased my first series of plywood for the construction of the bulkheads, frames, keel and stem. Finding the marine grade wood I wanted required a number of hours of research. There are a number of fine sources for plywood but I had a time of it figuring out the plywood I needed. My French building plans call for plywood in mm sizes and specified the number of ply’s with several options as to actual wood material. The Ebihen 15 calls for marine grade moabi, sapelli, sipo or equal. I did find Sapelli (sapele) wood which is very expensive in comparison to other US sourced marine plywoods. I could not source sipo or moabi plywoods. The majority of boat building plywood available from local sources are Douglas Fir, Okoume, Meranti, and Sapele. Douglas Fir was ruled out based on the large number of comments concerning the quality of this plywood and the problems douglas fir has with checking. Checking occurs when the underlying grain of the wood shows through the finished paint.
I limited my choices to either Okoume or Meranti. Okoume is the better choice if light weight is paramount in the construction. Meranti has better structual strength but is also 20% heavier. My intent with this boat is to have a stable cruiser and not a racer so more weight in the structure for me is not a liability. I ended up picking the Meranti. I figure my boat will be about 80 lbs heavier with this wood. I probably will purchase Okoume for the hull planking for both it’s lighter weight and easier bending ability. I am happy with my choice of Meranti for the structual components.