These bioluminescent plankton can get “activated” by the propeller on a torpedo. The glowing trail it left was one of the cues WWII sailors on deck watch would look out for. If you’re scuba diving at night in places where they occur, you’ll see these tiny glowing dots flicking off your flippers as you swim, as if you were kicking away fireflies.
If you are deep sea fishing at night the luminescence will trigger off your fishing line too.