National Geographic : 1971 Jul
Phantom sailor on a star-dust sea, a boatman churns a wake of fire in Puerto Rico's famed Phosphorescent Bay. His outboard motor, agitating micro-organisms that teem in the almost landlocked bay (below), stirs it into a maelstrom of luminescence. 80 TIMESLIFE-SIZE Unmasked by a microscope, Phosphorescent Bay's dominant light producers (Pyrodinium baha mense) glisten as yellowish single celled orbs. They swarm amid other irregularly shaped dinoflagellates. Pyrodinium, like plants, possess chlorophyll but can propel them selves by flailing two threadlike tails.