Key questions remain unanswered after a third inquest into the death of a diver in North Canterbury

Bua-Ngoen Thongsi died during a diving trip off the North Canterbury Coast in February 2015.

Her body was found just 100 metres from her last known position at a depth of about 10 metres.

The police dive squad found nothing wrong with her gear.. she had nearly a full tank and her gear worked during a reconstructive dive.

The coroner hasn't been able to establish who released air from Thongsi's buoyancy compensator, why it took those on the boat an hour to raise the alarm and why the search was so brief.