Glowing in the dark: Eerie phenomenon turned swimmers brighter shade of blue | Mail Online: ” Swimming is supposed to give you a healthy glow, but these swimmers weren’t quite sure what was going on when they took a late-night dip and turned a fluorescent shade of blue.
‘It was like we were playing with radioactive paint,’ said photographer Phil Hart who snapped the bizarre sight as his friends emerged from a lake in the dark of night.
The light is created by a chemical reaction called bioluminescence, which happens when a naturally-occuring micro-organism in the water is disturbed.”