Those who happened to be at Sydney's Manly beach last night were treated to some spectacular glow-in-the-dark waves.

The eerie blue waves were created by tiny bioluminescent marine animals called dinoflagellate, which live off a type of plankton.

Local photographer Joel Coleman - who filmed the above footage of the rare sight - said it was "super impressive" and he had rushed down to the beach to join the crowd after receiving a message from a friend about the waves.

"It was really special, it looked 'wow'," Mr Coleman said.

"It actually looks better in real life. To the human eye it looks quite intense and it's one of those things that is quite hard to capture on camera."

Mr Coleman said he had seen a similar phenomenon at Freshwater Beach four years ago in 2010, but nothing like it since.