Divers were treated to a once-in-a-lifetime experience when a humpback whale calf repeatedly swam and played over their heads.

The incredible footage was captured in waters off Jervis Bay, New South Wales, Australia.

Diving teacher Chris Wilson, 55, said he had never seen anything so incredible in 20 years on the job – and the group was left in awe at the playful and inquisitive nature of the giant of the deep.

Chris said the acrobatic youngster stuck around to play – with stunned divers waving at the huge mammal as it flipped around them – until it was summoned by its mother with a call and disappeared from sight.