A few years ago we were lucky enough to vacation in Vieques, Puerto Rico, home of the bioluminescent bay. If you've never had the honor of swimming in a bay filled with bioluminescent plankton, we highly recommend it. While there's not way to experience it without actually going, one pool company has figured out a way to harness the idea.
Atmosphere Piscines, based in France, has figured out a way for nighttime swimmers to get their laps in without the need of bright underwater lights. The company vacuum injects the pool's base with a phosphorescent coating known as "gel coat," which retains solar radiation during the day and then releases it at night -- sort of like those glow in the dark stickers you got in grade school. The vacuum injection prevents the emission of dangerous organic compounds. As the amount of solar radiation diminishes over the course of the evening, the pool changes colors as its intensity lessens. Pretty cool.
via House Automator