WATCH: Amazing aerial footage of orca hunting

Amazing aerial footage captured off the coast of the Mercury Islands shows orca hunting for stingray in the shallows.

Tauranga wildlife photographer Jack Preston was diving with friends on Sunday when two orca "appeared out of nowhere".

Using a drone, Preston followed the mammals as they hunted for stingray among the seaweed near the islands' shoreline.

The Mercury Islands are about 8km off the coast of the Coromandel.

"It's a real once-in-a-lifetime opportunity," Preston said.

Preston said the animals "appeared out of nowhere". Photo / Jack Preston photography

"Wildlife photography is very opportunistic and luck based, you can't just say 'okay today I'm going out to shoot orca', we were just in the right place at the right time and the conditions that day were perfect for photography and for flying the drone."

After hoping for years to snap a scene like the one he saw on Sunday, Preston said he was ecstatic the opportunity finally presented itself.

"The ocean and wildlife photography are my passion and I hope to be able to combine the two professionally in the future."

Preston shared the video on his Facebook page, where he said it was the most stunning footage he had ever captured.

Preston followed the animals using a drone. Photo / Jack Preston photography

Up next was a trip to Rarotonga, where Preston hoped to spot and film humpback whales to share with his Facebook followers.