A very rare Siebe Gorman underwater flood lamp,  These were made from solid gunmetal therefore very heavy, about 20Kgs to make them negative buoyant. Domed cover with swivel suspension and power inlet over a single bulb in a clear glass well with six bar bolt fixing. Makers plate in the oval space at the top of the lamp.  Measures overall 61cm high x 25cm diameter. Glass height 29cm.