Despite its ecological importance, the photosynthetic deep reef below 40 m around the world is understudied and poorly understood. Most coral reef science is performed within the depth limits of recreational SCUBA diving. However, zooxanthellate scleractinian corals occur far below these depths in clear oceanic waters (Fricke and Meischner 1985; Reed 1985; Fricke et al. 1987). In Hawaii, extensive deep reef habitat is associated with insular shelves which surround most islands, and which extend laterally several km offshore to depths of 110–120 m where they are typically bordered by steep fossil carbonate slopes created during periods of low Pleistocene sea level (Jones 1993; Fletcher and Sherman 1995).