Boulter has 4'x16' marine plywood sheets that are two 4'x8' sheets joined via "scarf joint".
I did not see any 4'x16' sheets on Marine Plywood. But, they do have 4'x10' sheets.
So, it looks like the best way to get a "stretched" version of the dory is to get 2 4'x10' and join them via "
scarf joint". This would give 20', which can be reduced to 18' or 19' accordingly.
But, it looks like a "
splice joint" is stronger than a scarf joint.
Thank you all for feedback thus far.
-Fish360