Sailors passing through the island of Vava'u, Tonga were treated to a beautiful and playful encounter with a mother and calf pair of humpback whales.

The calf is seen eyeing up the camera before playfully swimming under his mother, before both disappear into the distance.

The video was shot by Captain Marjan Golobic, who was sailing through the island as part of a global circumnavigation that started in St. Martin in the Caribbean.

The Vava'u lagoon serves as a breeding ground for humpback whales, where they look after their calves until they are strong enough to swim the open oceans.

Cow humpback whale with her calf in the lagoon of Vava'u Island, Tonga, which is the breeding grounds for humpback whales.