This is the astonishing moment a friendly whale shark swam over to fishermen in Thailand.

The curious marine animal floated over to the vessel off the coast of Prachuab Kiri Khan province on Tuesday afternoon.

Captain Theera said he was with tourists who rented his speedboat for a fishing trip.

They were enjoying the view while waiting for a fish to hook the bait when the giant creature appeared in front of the boat.

Footage shows how the whale shark calmly swam alongside the boat as the lads recorded it on a GoPro-style camera.

The whale shark stayed with them for around twenty minutes before it descended back into the deep water.

Theera said he did not expect to see the whale shark at all so he filmed the video to keep as a souvenir.

He said: ''The tourists rented my boat to go fishing. We went to a popular fishing spot and waited while they caught fish. They had been fishing for sometime when the whale shark appeared out of nowhere.

''We were all happy to see the animal. We didn't even look for it. It was a rare moment so I went down and recorded it.''

An official from the Department of Marine and Coastal Resources who heard about the unusual event said that marine wildlife had flourished in the area due to conservation efforts.

He said: ''We have been working hard for many years trying to improve the condition and the ecology of our area and I believe the presence of the whale shark is a sign that everything has been worthwhile.''