If you have access to cedar strips (or other) you can make panels out of strips. I did this for a Shearwater 17. I glued them together on a flat surface, then sanded and fiberglassed the inside. I then used the plans to cut them to size. I was then able to stitch and glue them together as if they were plywood. I then glassed the outside. I first did a test panel to see how much the would twist before breaking. It was not a problem for that boat. It turned out very strong and lightweight.

Dan

1.   You realize CLC would send you a kit with the ply already cut out?  Give customer service a call. You don't have to get the entire kit just the pieces you want. 

2. You might also ask yourself what is marine plywood?  It is clear plys with no voids and no footballs. It also has waterproof glue.  Exterior plywood has foot balls, sometimes voids and waterproof glue. Fisnish plywood, like ash or birch, is clear on one side and comes in thin sheets like the  plywood you build these boats with. These boats if made with cedar strips are often glued with carpenters glue because the wood core is encased in epoxy fibergass.  Do you see where I'm going? 

3. Pardon me, but I think the kit from CLC with shipping would be a better deal for you. 

Grumpy,

That mostly makes sense for customers in much of the continental USA, but once you get outside that area it can get very bad very quickly.

Laszlo