There's two different things: bioluminescence and phosphorescence.
Phosphorescence is a physical or chemical effect caused when phosphorus that is dissolved in seawater is stirred or disturbed by any kind of fast motion. Like a boat wake or oars, or uh... you relieving yourself.
Bioluminescence comes from light-emitting cells in living things like fish, jellyfish, or even microscopic critters.
Aha! So it was phosphorescence that I thought was an acid flashback happening in the water that night. Thanks for the clarification.
BTW, I have seen bioluminescence in North Pacific jellyfish while halibut fishing during the daytime. THAT would be something to see at night, full bladder or not!