An apparatus for providing a floating type of a boat dock or platform includes a plurality of synthetic material decking members that are disposed along the sides and top of the dock. Urethane foam is applied to an interior of the apparatus and it expands to fill the interior voids while simultaneously securing the decking members proximate one-another by securing them to the urethane foam. Accordingly, a monolithic structure is provided without the use of fasteners. Corner members are used that extend around an upper perimeter of the dock. Side members are used to form the sides, ends, and the decking material that forms an upper surface. An optional rounded member is preferably used at the bottom along a perimeter of the apparatus. Optional features, including elastomeric coating, filler blocks, utility conduits, sunken vaults, cleats, upper decking surface and waterline heating are also described.