The coating is a fluoro-urethane, developed jointly by the Naval Research Labs and the Electric Power Research Institute. The coating is hydrophobic, has a coefficient of friction slightly less than Teflon, and has been in use for about 20 years. The cost of the coating-$350 a gallon-has kept it relegated to specialty markets. Another supplier has a similar product at www.astridmm.com/sea-slide/sea-slide.html that you should test also.
First, I will assume the surface to be coated is thoroughly clean. A number of powder coatings can be painted over directly, using more of the same powder coating, a new powder, a solventborne or even a waterborne paint.