An Auckland family holidaying at their Orewa bach, were treated to a show of bioluminescent waves last night, some even dipping into the water to catch the glow.

Kane Metcalfe told 1News the family were sitting on their deck overlooking the North Auckland beach when his father spotted the luminous waves at about 10.30pm.

He said his brother’s family were also visiting from South Carolina and were so amazed, they decided to venture closer.

“My brother was like ‘let's go in it,’ so he took his two kids and wife into the water. They could see the glowing bits dripping off their hair and clothes - so they all ended up glowing,” Metcalfe said.

“They had never seen anything like that before. It’s a great exclamation mark to finish their holiday,” he said, adding the visiting family flew home to the US today.

Metcalfe said he’s never encountered the phenomenon.

“My parents have had that house since I was born and have never seen this before.”

Bioluminescent waves are rarely found on beaches around New Zealand, although more Kiwis are chasing the thrill of the blue 'bio' waves.

The phenomenon is caused by tiny blooms of phytoplankton that glow when disturbed, which is why they light up when they're hit by waves.

And more reports of bioluminescence across the motu are emerging.

NIWA algal ecologist Karl Safi told 1News last year "they seem to be increasing in incidence, people reporting them, but it could also be people just going out and looking for them more."