I was shipped a bunch of 3mm Okoume instead of the 4mm ordered. Repackaging it and shippping it back will be a major inconvenience/effort.

I am planning three stitch and glue boats; a 18'x 22" single, a 21'x26" double and a 21'x26" rowing scull.

What are the comparative strengths of 3mm vs 4mm for these sized boats? I have/use both 4 and 6 ounce cloth. Will I have trouble/weakness using the 3mm plywood?

I used 4mm for my hull and 3mm for the deck on a previous kayak.

thanks

Randy