Wheels of Poseidon

The Wheels of Poseidon are a biological phenomenon in which bioluminescent zooplankton create a luminescent wake from the bows of ships in the Indian Ocean. The perception from the luminescent wakes is that it resembles the spokes of a wheel, thus the name. (Poseidon was the Greek god of the sea.) The detonation of explosives underwater has also been observed to produce the effect.

Willy Ley talked about this phenomena in an essay written for Galaxy magazine, and published in book form in 1967 in Willy Ley's For Your Information: On Earth and in the Sky.