A British tourist has gone missing during a sightseeing boat tour in Thailand.

A British traveller has been missing for two nights after falling overboard into the sea during a sightseeing tour in Thailand, according to media reports.Wesley Bates, 35, a dual British-Australian citizen, fell into the sea off Koh Samui while on a speedboat on Monday while intoxicated, according to news reports. Chaktam Jaijong, the boat's captain, claims the group that chartered the boat (four men and one woman) ignored warnings not to sit on the bow of the vessel without life jackets.Jaijong said the group was already drunk when he picked them up for the tour, and Mr. Bates lost his balance in windy weather, falling into the water when they returned to the island around 4 p.m. A local resident added, "They didn't listen to me when I told them to sit properly because it was very dangerous to be on the bow of the boat. The tourists seemed very aggressive, so I didn't want to disturb them by allowing them to sit in the wrong place." Fishermen assisted Jaijong in searching for Bates before authorities were notified, but the search continued without success. Police Major Worasak Akarakul, an inspector at the Samui Police Station, said that despite all efforts, the British tourist has still not been found.