It is a surf ski, hull like a canoe flat deck with moulded seat and foot rests. If you capsize in rough water just climb back on and keep going. It won't sink unless you fracture the hull but by then you'll be among the rocks or under a ship.
http://www.dolphinsurf.com.au/compare_surf_skis.htm
This particular craft is rather fast, for going through big water at speed, paddled like a canoe.