Marine Plywood: World Panel Products (Low Okoume Prices)
Dimensional Lumber: Hardwoods Inc. of Alabama (205) 646-4160
Fiberglass Cloth and Tape: RAKA Boatbuilding Products
Epoxy: RAKA Boatbuilding Products
Hardware: Hamilton Marine (800) 639-2715
Jamestown Distributors
Sealers
Two Part Flotation Foam
Paint
The above materials list isn't the exact one that came with the plans. I deviated due to non-availabilty of some of the lumber in my area and also for personal preferences.
After reading and talking to some experts, I think I've picked up on the main things to consider when choosing plywood. There are many different types of marine plywood when you consider species, grades, and manufacturers. At first glance Douglas Fir seemed like a good choice. It's relatively light in weight, has a good strength to weight ratio, is moderateley durable, and is the lowest in cost. Futher investigation revealed some problems and caused me to re-think using it. The quality of Douglas Fir plywood has diminished in recent years. More specifically, the interior laminates of Douglas Fir plywood often have voids. These voids allow moisture build-up which can lead to delamination and rot. Another problem is Douglas Fir plywood is known to check, badly. This means that the exterior laminates develop cracks parallel to the grain, thus allowing moisture penetration.
Okoume (pronounced oh-coo-mee), a species of African Mahogany, has become a very popular choice for boat building in recent years. It's very light in weight, has a high strength to weight ratio, bends easily, seldom exhibits checking, and is readily available in high quality void-free plywood. Its drawbacks are it's considered non-durable and is expensive. The non-durable aspect doesn't seem to present a problem when encapsulated in epoxy. Most marine Okoume is manufactured to either British Standard (BS) 1088 or BS 6566. As I understand it, these standards require that the plywood pass boil tests without delaminating and be free of interior voids. The 1088 plywood has A grade exteriors, while the 6566 has B grade exteriors. BS 1088 Okoume is roughly twice the cost of Marine Fir. BS 6566 Okoume is about halfway between the two. Because my boat will be camo painted I'm not concerned with the plywood's exterior. After mulling it over for several weeks I decided on BS 6566 Okoume. I did use some BS 1088 since 5' x 10' panels were needed. The rest of my plywood was BS 6566.