Divers have captured the moment an enormous humpback whale breached the ocean on camera.

Craig Capehart and three other scuba divers were hunting for sardines along the coast of Pondoland, South Africa, when they spotted the whale - which they estimated to weigh around 40 tonnes - near the surface of the water.

To their delight, the whale leapt out of the ocean entirely, something rarely seen.

Capehart posted the amazing footage to YouTube, writing: "This day, there were few sardine sightings but the whales seemed to be everywhere! An unexpected bonus!

"This video shows a humpback whale mother cow swimming with a calf. It shows an adult 40 ton whale on its back, slapping both its left and right fins on the water, then leaping entirely out of the water!"

"Dolphins and even great white sharks have been seen flying out of the water, but this is a first for an adult humpback whale!"

He added: "A very rare event, indeed."

Some marine experts have suggested humpback whales breach the water to splash off parasites, but others believe they do it just for fun.

Humpback whales are huge - around the size of a school bus - and can grow up to 60 feet long. Their flippers can grow up to five metres long.

Humpback whale
Diver Craig Capehart captured the rare moment on camera Storyful/YouTube/Craig Capehart