A floating dock section is attachable to adjacent sections to provide floating dock structures of various configurations. The sections are formed by coating polymer foam with a polyurethane elastomer so as to seal the polymer foam. A decking is affixed to the coated foam with an adhesive which may be a polyurethane elastomer and extending downwardly from the decking are edge members that tightly grip the polymer foam. The entire structure is coated when assembled by applying a polyurethane elastomer of somewhat denser material and the decking itself may be suitably roughened to avoid slippage.