Ms Ong, an American aged 62, was the owner of Gekko Scuba Divers in Rawai, and also a Padi instructor and master scuba diver trainer.
Sydney’s The Leader newspaper reported that Ms Ong was diving with three other people around 10am. She was found unconscious and dragged to shore. A witness tried to revive her but she was pronounced dead at the scene by paramedics.
Police Detective Inspector Shane Woolbank said Ms Ong “was a competent diver with more than 15 years’ experience”.
‘‘There will be an examination of the diving equipment, particularly the air tank to see if there were any faults,’’ he was quoted as saying.
Ms Ong, also known by her nickname “Quero”, was well known in the Phuket/Andaman diving community. She moved to Phuket in 2005 and set up Gekko Scuba Divers, a private instruction dive school, in 2006. She was also a moderator on ScubaBoard.com, an online scuba diving forum.