
Witnesses said the Wararat, a tour boat carrying 20 people including guides and crew, was heading back to Koh Panyi for lunch on Monday when it collided with a long-tail boat carrying 12 Chinese tourists.
The crash caused Wararat to sink, but all 20 onboard were wearing life jackets.
Conditions were very rough at the time, with winds up to 25 kilometres per hour and seas up to 2 metres.
The passengers were fished out of the water by Phang Nga Bay national park officers and Phang Nga rescue teams. Boats in the immediate area also came to their rescue.
Sixteen passengers sustained injuries and were taken to Phang Nga hospital. The injured were four Belgians and 12 Norwegians, and their injuries were mostly minor, although one passenger was said to be in a serious condition.
The Wararat was on a trip organised by Khao Lak Asia Tour.
Koh Ta Poo was featured in the 1974 James Bond film “The Man with the Golden Gun”.