Don't let the "sea" in "sea kayak" intimidate you. Kayaks designed to work on saltwater will work just fine on fresh water. If you are paddling on a large body of water where the wind can get strong and you get waves, a sea kayak is probably exactly what you want. If you are paddling on a small pond or very sheltered water, take a look at recreational kayaks. A sea kayak will be more efficient for covering long distances, a recreational kayak will be more maneuverable for exploring in small areas.
A guide to building small boats with wood strips and epoxy.
