A friendly baby whale shark delighted divers when it swam up to them during a trip.

The juvenile marine animal spanning 13ft (4 metres) emerged from the water near the boat carrying 17 tourists for a snorkelling tour off the coast of Koh Khlum Island in Tran province, Thailand, on November 17.

Footage shows the whale shark gently gliding in the water as happy tourists greeted it. When it motioned to swim away, one of the divers said 'bye bye' to the animal.

BB Divers Company staff member Kheow Sangthong said: 'It was amazing. We stopped to prepare our equipment when it appeared. It was such a treat for us and our customers.'

Kheow added the animal left after ten minutes and they went on with the activity.

He said: 'We were so happy and the tourists were taking pictures and videos of it.'

The whale shark is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual measured 61.7ft (18.8m) in length.

It holds several records for size in the animal kingdom, including being the largest non-cetacean animal. It is found in the open waters of all tropical oceans and has an estimated lifespan of between 80 and 130 years.

Whale sharks are listed as 'Endangered' on the IUCN Red List and are included in CITES Appendix II. In Thailand, they are protected under the Wildlife Conservation and Protection Act.