Abstract: A high intensity running light fixture capable of submersion to substantial epths includes tungsten-halogen lamps housed in glass globe sealed to a heat dissipating base. The fixture avoids reduction in light transmittance of the globe by the improvement wherein a finned heat collector is disposed in the upper regions of the globe, with fins in close proximity to the inner surface thereof, and is connected by thermally conductive pillars to the base.

Abstract: An underwater light unit is constructed to be placed together within simi units around a ship anchorage on the bottom of a body of water. The construction of the optical portion of the housing permits the uniform illumination of said bottom with a high intensity light so as to produce good silhouette in the volume of water space located above the light units, as well as permitting direct observation of objects on said bottom. The optical portion and base portions interfit in such a manner as to have their watertight integrity remain uneffected by nearby explosions. The housing and mounting stake are constructed and arranged so as to provide a low mounting height above the bottom, so as not to interfere with the passage of surface vessels through the illuminated water space.