Float Drums offer durable dock flotation that can be easily installed for new floating docks that you want to build, or as a replacement for an existing dock system. These are a one-piece rotationally molded part which eliminates seams that could result in separation and leakage. The 0.150″ think shell is made of though virgin polyethylene with ultraviolet inhibitors. This tough shell prevents damage from the sun, saltwater, fresh water, debris, oil, gas, and marine organisms.