By Dave Moran.
In the April/May issue #153 (pages 50–51) we looked at the contributing factors that may result in a fatality.
The Police National Dive Squad have provided us a very comprehensive analysis of the various factors that combined to bring about a fatality. Due to the magazine deadline commitments we were unable to present this information in a visual manner that could be easily understood. We plan to have this sorted by the August/September issue #155.
We have created a graph from statistics provided by the Police National Dive Squad. This incorporates a period from 2008 to 2015 – 57 divers! (View graph at the end of this post.)
It brings home strongly that we just need to be more aware of what can turn a day out on the water into a tragedy.
It will be of interest to readers comparing present-day training methods with what was taught in ‘Australia’s First Qualifying Course’ that Ivor Howett did in 1953 (View pages 39–41, June/July issue 154). These days this course would be considered a technical diving course!
I look forward to receiving your comments. If you wish we will publish them in the August/September issue.
Dave Moran, Editor.
Comments from Bruce Adams, Officer in Charge, Police National Dive Squad
Recently, the Police National Dive Squad have completed several public dive safety talks following a number of preventable deaths this past summer.
The talks took place across New Zealand and have resulted in significant interest in the recommendations we have made to coroners.
Our original findings presented at the talks covered the past five years, but the latest research goes back to 2008. Since 2008, there have been 57 diving fatalities with 22 common contributors to the incidents.
Please note these are not coroners’ findings but are what our team have uncovered and raised as issues to the coroner. In particular, we highlighted the cluster of factors we see again and again.
In response to the most common factors, which were not adhered to when fatalities occurred, divers must ensure:
- They dive with a buddy and remain with the buddy during the ascent and descent.
- They are medically fit to dive and that regular medicals are completed.
- They monitor time and depth and avoid diving close to or exceeding their maximum limits of depth, time and experience.
- They are correctly weighted and are naturally buoyant on the surface.
- They complete pre-dive equipment tests on their own and their dive buddy’s equipment – including for leaks, correct fit or size and air quality.
Our aim is to involve everyone in the promotion of dive safety. We do not wish to deter people from a fun and healthy activity, but there are things we can all do better to ensure everyone makes it home at the end of the day.
Divers are responsible for their own safety but training establishments, dive clubs, friends and family can always keep driving home the basic messages needed to stay safe. This includes ensuring no diver dives alone, avoiding diving in adverse weather, avoiding alcohol within 24 hours of diving, and only diving when you’re healthy and fit.
If the conditions aren’t quite right, there will always be another day to head out into the water.
All divers should let their GP know about their sporting activity, and discuss any conditions or medications they are on which may not be compatible with diving. Divers need to ask the questions instead of assuming they will be fine. As a rule, divers should assume their medication or condition is not suitable for diving unless confirmed otherwise. Similarly, divers should be checking their health, age and fitness suitability for diving with a medical professional.
We are all impacted by the loss of a friend or family member at some stage in our lives but many of the cases seen in diving are avoidable. Police attend all of these incidences and similarly to road policing, we know that a slight change in approach or attitude can prevent a tragic result. I have no doubt that if everyone played their part in enforcing precautionary measures, we could avoid the loss of a loved one, mate or colleague.
The next public dive safety talk is on 6 July 2016 at the University of Auckland Underwater Club. Full information on page five.
The recent discussion of Wellington diving fatalities certainly drew attention. In fact it occasionally bordered on public hysteria. A systemic failure of diving was implied, particularly of the buddy system, and the statistic of 85% of divers separated was used to imply that separation was the main culprit.
Hopefully people have now calmed down and can see that there is no systemic failure of anything. Diving is as it’s always been, and the recent fatalities around Wellington are coincidence. If they’re not, then what triggers have caused this systemic failure? If there are any, they would be salient and traceable, which they’re not. And if Wellington, hypothetically and for example, goes the next five years without a fatality, then it would be traceable regarding what problems were solved and how; I eagerly await this explanation in five years’ time.
But let’s go national: the statistics did suggest that the main contributor to diving fatalities is diver separation, and it was labelled a cause in some media. Note that being alone can’t be causal regarding triggering the fatalities. One prerequisite for causality is to eliminate other possible causes, known as the condition of internal validity. So if a diver fails in some behaviour, which begins a chain of events leading to a fatality, is diver separation causal? If you answer ‘yes’, then you’ll have trouble establishing internal validity. This shows the error and irresponsibility of labelling things causal when they’re not.
When causality is suggested in such discussions, what’s typically meant is something like, “Could non-separation have contributed to survival?” The answer to this is yes, but it’s a distant yes compared to other preventative behaviours. An evolving systematic review of the diving-fatality literature that I’m doing already shows some trends for fatality triggers. The main ones appear to be running low on gas, which leads to an emergency ascent and then to a fatality; and being medically unfit, or simply not being fit enough, to dive. Non-separation could possibly contribute to survival relative to these factors, but better gas monitoring and getting a proper medical are better precedents, and better precedents are evident throughout the entire range of fatality triggers.
This review of the literature suggests more and more that relentlessly advocating the buddy system as the primary safety behaviour is advocating an ambulance at the bottom of the cliff. It’s effectively saying that it’s OK to let potentially fatal triggers occur because someone will eventually be there for you. But if divers monitored their gas better and had more stringent medicals if in the age-fitness medical-risk category, then prevention would be happening long before thinking ‘buddy’.
Thus it’s hard to tell exactly what the statistics presented
by the police mean. They’re undefined in precisely what they are, and the surrounding commentary is so vague and unqualified it’s impossible to tell. Some of the numbers are also serious anomalies compared to international data (85% diver separation – really?), and unaccounted for anomalies simply add to the confusion, as do unexplained statements about multiple contributors.
No one is advocating abandoning the buddy system, but a little less obsession with it relative to the evidence would be refreshing. If the diving agencies and public authorities made an effort to properly look at the evidence, developed the expertise to determine its best meaning and then communicated it in a publically-responsible way, then we could possibly have different diving recommendations that could be genuinely safer. But this would require a change in culture to evidenced-based practice and away from the tiresome habit of broadcasting outdated clichés. But really, what are the chances of this ever happening?
I have just read your article in Dive Pacific titled ‘9 Divers in 3 Months’. I totally agree with your comments, I have been diving for over 45 years and was initially trained in Perth by ex-navy divers in the Western Australia underwater explorer club (before formal training was required). The training was at times quite brutal for a then-teenager. It wasn’t uncommon to be physically hit upon exiting the water if you had done something really dangerous. As a result, I still remember being told every dive is a risk to your life so treat the dive accordingly.
Some years ago I dived the Yongala wreck off Townsville with a commercial dive operation. I was horrified to see the level of training being given to students. We did a number of dives over three days on the reef at 10–15 metres, with the last one being the Yongala. When I questioned the Dive Master as to why we were doing the deepest dive last he couldn’t see any problem! I asked “What about my residual nitrogen?” To which he replied, “You have been to sleep last night so there won’t be an issue!” When I showed him my dive computer, which indicated I had a safe bottom time of less than five minutes and as a result I didn’t dive on that occasion, he was amazed with my decision. I did dive the wreck at a later date.
I consider myself a very cautious diver but I’m still alive and have never had a serious safety issue in my diving all over the world. I think the dive training requires a serious shake up otherwise this concerning trend in dive deaths will continue.
Keep up the good work. Regards, Neil Yates
- The buddy was not within range to assist
- Medically unfit to dive
- No pre-dive equipment check
- Not knowing computer or following its recommendations
- Over-weighted, not neutral at surface
- Gear not serviced
- Diving with faulty equipment
- Divers exceeding training experience
- Failure to monitor gauges (out of air)
- Not surfacing with agreed minimum air/gas
- Not all divers knowing the plan
- Not carrying a knife
- Extended break from diving with no refresher
- Diving close to maximum of depth, time and experience
- Exceeding safe ascent rates
- Consumption of alcohol
- Catch bag attached to diver
- Prescription drugs
- Feeling unwell before the dive
- Not monitoring weather or sea conditions
- Dive watches not worn and exceeding maximum time
- Free divers not using the one-up one-down rule – not knowing where their buddy is.
I look forward to receiving both your positive and negative feedback. Email: Davem@divenewzealand.co.nz
View past coroners’ reports at http://divenewzealand.co.nz/safety-health/coroners-and-accident-reports/