This is a design for a basic hull made from one piece of closed cell foam 1m x 4m x 50mm thick. The trade name is Plastazote and there is a distributor in the USA.
The hull can be used to develop a rowing skiff, canoe, kayak or sailing trimaran.
It is part of a project to develop a boat suitable for promoting water sports in developing countries.
Make a boat and contribute your ideas to the project: www.theopenboat.org