Lt Sakrin Saengcharoen of the Chalong Police was notified of the incident at 3:30pm.
The body of the tourist, Zhu Kai, 31, from Tianjin, was brought back to Chalong Pier, and transported to Vachira Phuket Hospital in Phuket Town.
Mr Zhu had booked a day trip to Koh Racha through tour company Similan Pro Dive on board the boat Chot Somporn 18, Tourist Police noted in their report.
Mr Zhu was travelling alone and was staying at a hotel in Patong, police added.
The tour guide leading the group, Wanchai Sae Lo, told police that the boat had moored in Patok Bay and the tourists had lunch before being set off on a free time period of the tour.
“Before we let them go I explained everything to them about safety and they all said they understood the instructions,” Mr Sae Lo said.
Mr Wanchai explained that while other tourists stayed on the beach, Mr Zhu walked further along the beach and went snorkelling alone, Capt Ekkkachai Siri of the Phuket Tourist Police told The Phuket News this morning (Jan 9).
“Then when they called the tourists back to the boat, they could see where Mr Ahu was, but he was not responding to any their shouts,” Capt Ekkachai said.
“The boat drew rushed over to help him and brought him on board the boat, but he was already unconscious. They tried to revive him, but could not,” he added.
Capt Ekkachai noted that police were now working with Chinese consular officials in reporting the death and arranging for his body to be repatriated back home.
Additional reporting by Tanyaluk Sakoot