A shark-detecting drone has revealed a great white predator swam menacingly close to a surfer near the 'shark attack capital' of Australia.

Video from the airborne surveillance device has been released by the NSW Government from a trial it held off Lighthouse Beach at Ballina, on the far north coast, where in September 2016 a teenage surfer suffered a horrific leg injury in a shark attack.

There have been at least 11 attacks, two of them fatal, in the 70km stretch north from Evans Head to Ballina and Byron Bay since 2014, reports The Australian .

Video shows many little seen creatures of the ocean such as eagle rays.

It was one of several drone flights that have been held in the state over the summer to test the effectiveness of the land-piloted aircraft in detecting shark movements.

Footage taken at 60m above the ocean revealed myriad marine life that are often unseen by surfers, swimmers and sailors including a ray, green turtles, dolphins and a leopard shark.

The clip ended with a surfer unaware of a great white shark heading within a few metres of his board before it suddenly veered away.

The drone is controlled from a pilot on the beach and captures marine life including shoals of fish.

Pilots based on a nearby cliff fly the drones around a 5km circuit of water, with an on-board camera providing real-time vision of coastal waters.

When a shark poses a risk to swimmers or surfers details are passed immediately to police and lifeguards.

NSW Primary Industries Minister Niall Blair said at the launch of the trials last December: "Sharks which are posing a potential danger to swimmers and surfers will be immediately reported to police and local surf life saving clubs at patrolled beaches."