DIVERS ALERT NETWORK FREEDIVING ACCIDENT DATABASE REVIEW: 2006-2011
Neal W. Pollock, PhD; Mary F. Riddle, BA; Jenna M. Wiley, BS; Stefanie D. Martina, BS; Mitchell N. Mackey, BS Divers Alert Network, 6 West Colony Place, Durham, NC 27705
- Breath-hold diving – commonly known as freediving- an in-water activity with a mask but without the use of scuba or surface-supply breathing gas, has grown in popularity as an underwater activity with numerous sub-disciplines.
- While generally safe, the aquatic realm is unforgiving and serious injury or death can occur. Learning from freediving accidents is important to increase diver awareness and promote safety.
- Divers Alert Network (DAN) developed a dedicated database to collect freediving accidents (or incidents) from 2004 forward.
- Cases are identified through automated keyword internet searches and voluntary submission. Incidents are followed up through requests to participants or local authorities.
- We reviewed cases from 2006 through 2011.
- Data are reported as number (n) of cases and/or mean±SD with ranges.
- The percentage of known data is specified for variables with incomplete records.
- A total of 417 freediving accident cases were captured; 308 fatal and 109 non-fatal.
- 51±9 (40-63) fatal cases annually (Figure 1).
- Incidents were reported from 56 countries.
- 46% in America; 11% in Australia; and single digits elsewhere.
- Freediving victims were 41±17 (5-93) years of age (92% known) (Figure 2).
- Most freediving victims were male (86%).
- Dive activity was described as snorkeling (46%), spearfishing (25%), freediving (18%) and collecting (11%) (92% known).
- Incidents were reported in ocean (90%), swimming pools (3.6%), lakes/quarries (3.3%), rivers/springs (1.8%) and other (1.3%) (94% known).
- Witnesses were present in 61% of cases (64% known) but generally with incomplete details of the event.
- The majority of victims were diving with a partner or group (59% known) (Figure 3).
- Disabling injuries were most obvious with acute animal or boat trauma. The most common disabling agent was loss of consciousness, typically intuited in fatal cases from witness reports and/or circumstances due to the lack of physical evidence.
- Initial triggers were frequently impossible to confirm in fatal cases.
- Excessive hyperventilation was most frequently suspected.
- Health issues implicated for many older victims.
- Freediving can be conducted with minimal equipment and training, attracting participants from novice to elite competitive.
- Identifying the root cause of accidents is critical to incident analyses.
- Deficiencies in witness reports and the frequent lack of physical evidence make evaluation of fatal events difficult.
- Triggers and disabling injuries are often difficult to ascertain.
- Excessive hyperventilation is the most common trigger found.
- Capture of non-fatal incident data for which firsthand information can provide a more complete picture of contributing factors is essential to improve our understanding.
- This requires a recognizable and convenient means to submit incident data and community support.
- Freediving accidents frequently present with incomplete history and poor physical evidence.
- Excessive hyperventilation is the most commonly identified risk.
- Additional information is required to identify triggers and disabling injuries. Fully detailed non-fatal case reporting will likely be critical to improve our understanding of contributing factors.
Mary Riddle, Jenna Wiley, Stefanie Martina and Mitchell Mackey were supported by 2010-2011 DAN research internship programs.