DAN Report on Diving Fatalities

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NWgratefulldiver:
Here is more at what I was getting at. While you may not define diving as a sport, we both agree that it does take some level of fitness. Maybe my choice of words was not great, much like people think of sport star as heros.:shakehead: I am by no means a dr. nor do I pretend to be one.

When fit people get heart attacks

SCUBA diving instructor Carlson Victor Lee was the picture of physical strength, able to swim against an oncoming current when other divers would be sheltering behind a rock. He also owned a dive shop in Batam View Hotel where he conducted diving trips. On August 10, 2002, he died during a dive, triggered by a heart attack.

Running guru James Fixx was the author of The Complete Book of Running, that helped popularise jogging in America. He died of a heart attack while jogging on July 20, 1984.

When you read of these and other reports of sports individuals who suffered a heart attack or sudden cardiac death while playing tennis, diving or running, you may get the impression that vigorous exercise is dangerous to the heart.

Is that so?

A heart attack occurs when blood flow to the heart is critically reduced or completely blocked, causing chest pain. If not treated promptly, the affected heart tissue dies. Before an attack, most victims experience angina (chest pain) that is provoked by blockage of blood flow to the heart. With angina, blood flow is quickly restored, the pain recedes within minutes, and the heart is not permanently damaged.

However, a third of all heart attacks occur without warning signs. The victims suffer from sporadic interruptions of blood flow to the heart that, for unknown reasons, are pain-free, although they gradually damage the heart tissue. The heart is therefore already damaged even though the individual appears fit and strong.

But during vigorous exercise such as jogging, the person who already has a damaged heart or an underlying heart disease, is more likely to die than if he or she were walking or resting. In exercise, the heart may develop an irregular beat, blood pressure can rise to a dangerous level or plaque from a partly-clogged artery can break off and stop blood flow. The arteries supply blood to the heart muscles, bringing to them oxygen and nutrients.

In the case of scuba diver Carlson Victor Lee, autopsy indicated that the front part of his heart was paler than the rest of the organ, indicating the blood supply had been cut off, consistent with a heart attack. Fat was found in the coronary vessels and it was also clogged all around the heart. There was significant thickening on the ventricles, an indication of a heart that had been made to work harder and harder due to increasing resistance in the coronary vessels.

As for James Fixx, he had a family history of heart disease; his father suffered a heart attack at 35 and died of one at 42. He himself experienced cardiac symptoms in the weeks before his death, symptoms of one or more smaller heart attacks that he ignored.

Fixx took up running in 1967 at 35 years old. He weighed 214 pounds and smoked two packs of cigarettes a day. Ten years later, he was 60 pounds lighter and smoke-free. In his books and on television talk shows, he tells how physical exercise had considerably increased the average human being's life expectancy.

Fixx died at 52 of a massive heart attack, during his daily run, in Hardwick, Vermont. The autopsy revealed that cholesterol had blocked one coronary artery 95 percent, a second 85 percent, and a third 50 percent.

Some critics said his death was proof that running was harmful. But given his family history and his unhealthy lifestyle until he took up running, others argued that running has indeed added many years to his life.

The heart is a muscle, and like any other muscle, exercise conditions it to be stronger. A well-conditioned heart pumps in 50 beats per minute the same amount of blood that the heart of a sedentary person would pump in 75 beats per minute. In addition, during rest, a well-conditioned heartbeat is slower. This means the heart does not have to work as hard to get the job done, so the heart rate slows down.

The underlying causes of most heart attacks are high blood cholesterol level, high blood pressure, obesity, diabetes and undue stress. Regular physical exercise counters every one of these risk factors. Exercise also raises blood levels of HDL cholesterol, which helps to cleanse the arteries of deposits.

The main risk factors that exercise cannot change are family history and age. These two factors can serve as a warning. So, if you have family members who have heart attacks before age 65, or if you are middle-aged or older and have been sedentary for years, you should go through a physical checkup before taking up running and other vigorous physical activity.

– Francis Chin, September 2006
 
Bob,

I do not see sharks as dangerous and I know how to never run out of gas, as do my divers after completing my Open Water class - just pointing out two questions/fears brought up by many new students here in Texas. Also, I read your Gas Management article posted on your website... good work.
 
Before eliminating medical event related deaths while SCUBA diving from total SCUBA fatalities (which, to me, seems to be a "feel good" thought that certainly brings the number down to a far less severe total), consider the following. The logic seems to be that the event would have happened anyway, during any other type of activity (and not necessarily require or be indicative of severe exertion). But how many of those events would have been survivable had they occurred on land? The tragic recent embolism suffered by a young diver during a boy scout outing comes to mind.

Yes, some medical events are truly deadly even were they to occur in a hospital waiting room. But I don't need to read a DAN report to conclude that the death rate from heart attacks or other events must skyrocket should they occur underwater.

Learning to dive at 49, I knew there were risks I was (and am) incurring. With no negative family medical history I chose to get checked, stay monitored, regularly exercise to improve fitness and reduce the risks, and dive.

Maybe we were lucky, but our OW instructor spent a fair amount of talk time ensuring that we KNEW there is no excuse ever to run low/out of air. In addition, we spent time in the pool mastering a hover 3' off the bottom (cross-legged / yoga type position and horizontal) and practicing skills while neutrally buoyant before our check-out dives. We had some extra pool time available because we kinda sailed through the various basic skills, and our instructor had more time with us after washing out THREE other students (he was wise - they truly had problems with basic swimming skills and fitness). Having no basis for comparison, I remain surprised that OW classes don't generally work on bouyancy, and on the poor bouyancy we have observed in the water in our limited experience.
 
I'm planning on a doing a cave penetration of about 1000' and 200' depth. I'll only be using a steel 72 and haven't had any cave experience. I'm sure I'll be alright tho.:eyebrow:
 
I'm planning on a doing a cave penetration of about 1000' and 200' depth. I'll only be using a steel 72 and haven't had any cave experience. I'm sure I'll be alright tho.:eyebrow:

It sounds as if you are totally prepared for this, well thought out. Make sure you post how things went after you come out.:shakehead: It will also be solo??

Of course I am joking!!!!!
 
Kool Aid drinkers? I don't recommend ponies for my OW students. I would rather get them grounded in gas planning and management from the start. One guy on the boat was quite surprised that I surfaced with 1500 and 1800 psi on two dives this past Sunday. Could I have have used more air? Sure... but why? I accomplished what I set out to do and was as close to deco as I wanted to get.


I have easily over 6000 hours underwater. Number of times I've carried a pony bottle? 0
Number of close calls I've had that could have been changed by wearing a pony bottle? 0

Guys, it is your responsibility to not run out of air. If that's important to you, there is no need for a pony bottle in open water. Pete, I agree with you completely. Teach students how to manage their air and there's no need for the $200+ investment. If they can't get the basics down, adding another bottle really isn't providing them any more protection. There is no reason for emptying your primary gas if you are following the instruction you were given in OW.
 
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shouldn't we thus be spending the majority of our Open Water Training time on ways to ensure divers don't run out of/low on air

So what do any of the instructors, or anyone else for that matter, think should be done/taught that would improve on what is being taught now in regard to "out of air" or "low on air" situations and how to avoid them?

I know it's been almost 20 years since I was certified but I still remember my OW course and my first instructor. He emphasized on more than one occasion, especially for a new diver, to frequently check your depth and pressure gauge. I even remember on the checkout dives that he would hold up his gauge to us during the dive and point to his head as if to say, "Remember to check this".

So my question would be what more can an instructor do. I mean diving ain't rocket science and people should have more than enough common sense to be checking their gauges on a frequent basis. That doesn't mean it's going to happen of course but can you really do anything about a person that just forgets to check his gauges? Would emphasizing it 20 times during a course be any more effective than say 10 times?

This is all assuming, of course, that the majority of OOA situations is just simply not watching your gauges like you should.

One good thing about most computers now is that you can set an alarm that will go off when the tank pressure reaches some preset level so that could help get a persons attention if they are forgetting to check. But while that is better than nothing I guess, it's still not the answer to forgetting to check.

If you're a good instructor, I just don't know how you guys can really do anything different.
 
In my OW training there was by the book discussion of DCS, OOA, and other dive related risks...I think there might be a module on it in the PADI OW book even. My classroom and pool instructor was quite good I thought but looking back on it now, we didn't really do anything to far above and beyond. He did teach us what it's like to run out of air by turning off our tanks, and we did some basic buoyancy work and free swimming. My advanced course didn't really advance my skills or knowledge in leaps and bounds and touch on nothing which I think would really help me become a better diver beyond the basic navigation skills.

The greatest knowledge I've gained since the official training I received was in attending a free 30 minute talk by the dive shop owner while on two recent dive trips in Roatan. I received more diving tips in the half hour talk and have come to a greater understanding of how buoyancy improves the overall diving experience than in all my training.

I've dropped pounds off the weight belt, better understand trim, better understand how to descend, better understand how to adjust the air in the BC, and am now a much better overall diver. I used to be one of the first to be signaling half a tank of air and now I'm coming back up with just under half a tank left. My personal safety has gone way up as has the safety of my buddy and anyone else we dive with. The marine life is also much safer. I now feel confident I won't damage the surroundings as I float in to take a picture of that seahorse attached to the bottom of the coral.

On my last trip in August, I contrasted my experience with the experience of another diver on our boat. He carried a large SLR camera with him, two strobes, and would thrash around in the water to stay buoyant and then mash his big camera into the sea life as he literally sunk to the floor as he took pictures. He would also be signaling he was at half a tank before I had used a third and was often coming up with 500 or less in his tank. From what I observed he could easily end up adding to DAN's statistics. With a little more training and a little more care, he would become a much safer diver.

EDIT: To BDSC's question, I think instructors can only do so much and then it's the responsibility of divers. I believe instructors do a good job of drilling into their students heads they should check their gauges. As I harped on above, I think more emphasis on buoyancy would be a great thing. Making the buoyancy specialty a mandatory part of an advanced course might be a start.
 
In the real world, the Basic Open Water class has a pretty limited time frame in which to present the information. In the PADI "world" (unlike the NAUI world for example) the curriculum is pretty darn structured and we, as instructors, are required to have our students answer the "Knowledge Reviews" and take the standard tests (assuming we are even directly teaching them as opposed to having them do the "academics" online). In both the Knowledge Reviews and the tests, a significant amount of time and energy is taken up by solving NDL problems using the RDP (in its various permutations). There is really Zero time and energy spent on how to plan on not running out of air (there is some discussion/questions but it isn't much and no where near the amount spent on NDL issues).

Many instructors do "sneak in" discussions, on a pretty basic level (after all, it is Basic OW) concepts students may need to do some basic gas planning -- that is, more than "check your spg" which is all after the fact execution (NOT planning).

Since there is, in reality, a limited amount of instructor/student time and energy, I wish we'd be able to ditch the NDL discussions and spend the time on those issues which, in fact kill beginning divers -- running out of air and losing buoyancy control.
 
So what do any of the instructors, or anyone else for that matter, think should be done/taught that would improve on what is being taught now in regard to "out of air" or "low on air" situations and how to avoid them?
...

So my question would be what more can an instructor do. I mean diving ain't rocket science and people should have more than enough common sense to be checking their gauges on a frequent basis. That doesn't mean it's going to happen of course but can you really do anything about a person that just forgets to check his gauges? Would emphasizing it 20 times during a course be any more effective than say 10 times?

I think this is a really good question that you should repeat in the I2I forum.

I assume we all teach the "what's your air?" signal and a way of responding to it in the CW dives, but how often do we do it? Analyzing my own practices, I think that in the focus on doing skills and working on buoyancy, I probably don't do it enough to help make it a habit for the divers. I am not sure I can do it enough to make it a habit in the amount of time. Additionally, the way we do the dives in confined water, we don't use enough air to make it enough of an issue to make it any more than an academic exercise.

Although I do talk about determining your SAC rate so that you can plan your air in the OW class, it is also just an academic exercise because these people have no clue about their use of air, and we have no way of knowing it at that point either. Another instructor and I recently each did an AOW deep dive with a diver whose SAC rate was so horrible that the number one lesson the diver learned was that he had no business doing a deep dive until he was able to improve it. If each of these divers had done their deep dives without an instructor watching them, they would have gone OOA because they would have been OOA before they thought to check their gauges.

In each case, neither the other instructor not I had ever seen a diver with such a bad rate. They were not particularly good in their previous AOW dives with us, but they went through the roof with air usage on the deep dive. So perhaps in the OOA statistics we are often looking at a particular subset of divers who go through their air at a stunningly fast rate and don't realize it until they put themselves in that situation.

If so, then perhaps the answer is not just making sure they look at their air from the start, but also making sure they are skilled, competent divers from the start, divers who are not going to suck down their tank in minutes, divers who will not suddenly start sucking down their tanks when they go beyond 60 feet. Both of the divers I mentioned were from out of state and had not done their initial training with us. What did their initial training look like? We have no idea.
 

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