From June to September, for the three nights following a full moon, Bermuda's glow worms engage in their phosphorescent mating display. Exactly 56 minutes after sunset, in the shallows around the Island, the females come to the surface and while swimming in circles, emit their eggs in green bioluminescent clouds. Nearby males, flashing excitedly, streak towards the female, ejecting their sperm in a passionate display of marine fireworks.
The whole show lasts for less than 10 minutes. One of the best places to see it is under the bridge that you cross on the way to the cache (see waypoints for coordinates), as it's easy to get to and there’s little extraneous illumination to mask the worms’ display.