Underwater Pressure-Resistant Polyethylene Buoy We specialize in producing polyethylene floats for dredging. The outer body of the polyethylene float is orange-red, which can be used as a warning sign to effectively prevent ships from hitting pipelines. Underwater pressure-resistant polyethylene floats are resistant to motor oil, gasoline, and diesel.​It is better to be careful when using them. They are mainly used for laying oceans, salt lakes, fisheries, underwater oil, and dredging pipelines.