Bioluminescent dinoflagellates (Lingulodinium polyedrum) lighting a breaking wave at midnight. The blue light is a result of a luciferase enzyme (like firefly luciferase, but the enzyme in L. polyedrum shares no similarity with that of the firefly enzyme). Under the right conditions, the dinoflagellates become so numerous that the water takes on a muddy reddish color (hence the name "Red Tide"). The bioluminescence is only visible at night. The photo was taken 6/26/2005 with a Canon Rebel XT - 6s, f5.6, ISO 1600, 85mm (135mm equiv).