Colin Peters thought it would be an enjoyable day of deep sea diving, along with Jim Self, at The Puddle off the Calf of Man – near the Isle of Man, an island located between England and Ireland.

It was, but for an unexpected reason. He was joined by a friendly seal, who swam up, patted him on his head, and decided to play. At first the divers were apprehensive, but once they realised the seal meant them no harm, they played too.

Both Peters and Self captured the enthralling – and heartwarming – footage of their adventures with the seal (video above).