The present review summarizes the problems faced by reef building, zooxanthellate corals by the over two orders of magnitude in the underwater light field over their bathymetric range. The different levels by which corals optimize light harvesting and utilization are discussed on the molecular, biochemical, biophysical metabolic, behavioral and architectural levels. We show how the high energy striking shallow water reef tables is used, while avoiding its destructive photodynamic potential, and elucidate the means available to dim light, deep water coral colonies to survive on that meager resource.