San Diego surf turns blue in weird natural phenomenon

These beautiful pictures show a Californian beach lit up by bright blue waves.

Locals in the US captured the natural phenomenon on their phones and cameras as the waves crashed ashore.

The effect is created by plankton that glow blue at night when they are moved by waves or motions in the sand.

During the day the plankton are coloured red - which is why this natural feature its known as a red tide.

Check it out.