Table 3. Chain of Events Analysis of snorkelling and compressed gas diving-related fatalities in Australian waters in 2012; CAGE – cerebral artery gas embolism; He – helium; IPE – immersion pulmonary oedema; OoG – out of gas .

Case	Predisposing	Trigger	Disabling agent	Disabling injury	Cause of death
BH12/01	Planning	Unknown	Unknown	Asphyxia?/IPE?	Drowning
BH12/02	Health	Environmental/Exertion	Medical	Cardiac incident?	Drowning
BH12/03	Health	Unknown	Unknown	Asphyxia?	Delayed drowning
BH12/04	Health	Environmental/Exertion	Medical	Cardiac incident	Cardiac-related
BH12/05	Health	Environmental	Medical	Cardiac incident	Cardiac-related
BH12/06	Health/Planning	Environmental	Medical?	Asphyxia	Drowning
BH12/07	Supervision	Unknown	Unknown	Asphyxia	Drowning
BH12/08	Organisational	Environmental	Unknown	Unknown	Unknown
BH12/09	Planning/Activity	Extended apnoea	Apnoeic hypoxia	Asphyxia	Undetermined (Drowning?)
BH12/10	Equipment	Unknown	Unknown	Asphyxia?/Cardiac incident?	Undetermined (Drowning?)
BH12/11	Organisational/Experience/Skills	Exertion	Medical	Asphyxia	Drowning
BH12/12	Organisational/Planning & Supervision/Health?	Environmental/Exertion	Medical	Cardiac incident	Drowning
BH12/13	Planning/Activity	Extended apnoea	Apnoeic hypoxia	Asphyxia	Drowning
BH12/14	Equipment/Experience/Skills	Gas supply	Buoyancy	Asphyxia	Drowning
SC12/01	Equipment/Heath/Supervision	Unknown (gas supply?)	Ascent?	CAGE?	Drowning
SC12/02	Health/Equipment/Planning	Environmental/Exertion?	Medical	Cardiac incident	Drowning
SC12/03	Health	Environmental/Anxiety	Medical	Cardiac incident	Drowning
SC12/04	Health	Environmental	Medical	Cardiac incident/SDPE?	Cardiac-related
SC12/05	None identified	Environmental	Gas supply	Asphyxia	Drowning
SC12/06	Equipment/Experience	Equipment	Environmental/Equip/then OoG/Impact	Asphyxia	Drowning
SC12/07	Activity	Environmental	Environmental (shark attack)	Trauma	Trauma
SC12/08	Health	Gas supply	Equipment	Asphyxia	Drowning
SC12/09	Skills/Planning	Buoyancy/Diver error	Gas supply/Buoyancy	Asphyxia?	Drowning
SC12/10	Health	Environmental	Medical	Cardiac incident	Cardiac-related
SC12/11	Health/Activity	Gas supply	Gas supply	Asphyxia (He)	Asphyxia (He)
SS12/01	Organisational/Training/Experience/Supervision	Unknown	Unknown/Gas supply?/Ascent?)	Asphyxia?/CAGE	Drowning