Metro Marine High-Output Vertical Surface Mount Light w/Intelligent Monochromatic LED's - Blue, 90° BeamHigh Output Vertical Surface Mount Light with Intelligent Monochromatic LED's Blue, 90 Beam The F Series line of underwater marine lighting fixtures is designed to mounted a depth of up to 4. 6M (15') below the waters surface to provide vibrant Blue light in the water. With watertight aluminum bronze housings and silicon bronze hardware, Metro Marines F Series luminaires are perfect for marine based applications such as mounting to yachts, docks, sea