Akemi Kato, 52, failed to show signs of life as an ambulance carried her to Krabi Hospital.
The family arrived in Krabi yesterday to begin their seaside holiday.
Phuketwan has been told that Mrs Kato had never snorkelled before.
She got into difficulties at Kai island, a short ride by traditional longtail boat from the resort town of Ao Nang, or Railey, where the family was staying.
Needless deaths have been occurring off Phuket especially because tourists are often not taught how to use a snorkel before going into the water with one.
Often, someone who is taking in water through a snorkel will show no obvious signs of being in distress.
Some time later, people nearby will notice they are not moving.
The death of a Japanese tourist is unusual.
Most previous snorkelling-related drownings have occurred among Chinese visitors, who are coming to Phuket and Krabi in increasing numbers.
Just where is the leadership in Phuket? There is a man mysteriously insisting on fussing over 10% of beach quota spacing while people are dying because the tourism industry is nowhere near regulated. Every governor in my memory has risen to the 'challenge' of an overseas junket ostensibly to 'learn more about the tourism industry' but no improvements have been instigated, least of all safety measures.
Posted by Sam Wilko on April 14, 2015 16:50