Inquest into the Death of Syoko Tsubaki

24y · Female·Immersion (drowning due to hypoxic brain injury)

Syoko Tsubaki, a 24-year-old Japanese tourist and inexperienced recreational diver, died from drowning on 31 December 1998 after a scuba diving incident at Rottnest Island on 27 December. During an afternoon dive, the dive guide Kazumasa Miyahara ascended with the deceased when her air supply became critically low, but left her alone while returning to collect the remaining four divers who had not surfaced. The deceased encountered difficulties and was found floating face-down approximately 10-15 minutes later. She was resuscitated by rescue personnel but suffered severe hypoxic brain injury and died from the effects of immersion. Key failures included: the dive guide navigating the group 100-150 metres from the vessel, ascending without ensuring all divers surfaced together, failing to ensure proper buddy pairing and communication, and critically, abandoning the distressed diver alone in choppy conditions. The coroner concluded the death was accidental and supported recommendations for industry-wide safety standards including mandatory rescue craft provision and proper dive guide protocols.