As we pointed out in the spring 2013 edition of the Alert Diver, even being a dive buddy has potential legal implications. So, to bump this up a notch, what about the diver training organisations themselves? Where do they stand? How do they relate to South African law? Are they all considered the same under our legal system in spite of the differences in organisational structures and training programmes? How does this affect their respective instructors and trainee divers from a legal perspective? These are not exactly simple questions. It is certainly true that the respective training organisations differ in a number of ways. However, this does not imply that there are necessarily differential legal implications for each of them. In fact, under South African law, the legal principles are common in all matters. Therefore, if you suffer a loss and you (or your estate in the case of a fatality) wish to recover damages, the legal principles would be applied commonly; whether you are driving or diving. Although not a frequent occurrence, there have been quite a number of law suits associated with diving injuries and damages in South Africa. This is not surprising, as the occurrence of law suits is really a function of “numbers”. As training increases, so do the chances of injuries and, with it, the chances of legal recourse. So, it remains wise to insure yourself, your equipment or your business in a proper and effective way. But before getting back to the potential differences amongst the training agencies, let’s first explore the foundational legal principles on which any civil claim would be adjudicated: inherent risk, negligence and duty to take care.
RESEARCH, EDUCATION & MEDICINE FROM THE MEDICAL LINE Aging and Diving DAN MEDICS AND RESEARCHERS ANSWER YOUR QUESTIONS ABOUT DIVE MEDICINE. Q:I am 79 years old and healthy. I have not been diving in several years and would like to get back into it. Are there any recommendations, prohibitions or limitations for a diver my age? note that DAN® is not a regulatory agency and does not set standards or A:Please guidelines for participation in diving. Any age or fitness limitations you encounter would come from training agencies or dive operations, not DAN. The responsibility for the decision of whether or not to dive is generally that of the individual and his or her physician. This decision, however, should be based on the most current diving medical information available. Many people in their 70s and 80s continue to dive, although their diving style may change over time. The key to safe diving is physical fitness, not age. Or as some people glibly state, “It’s not the age but the mileage that counts.” An athletic, physically fit senior citizen may be a better candidate for diving than a 25-year-old in poor physical condition. But that same person will never match the physical capabilities of an athletic 25-year-old. All tissues — blood vessels, heart, lungs, muscles, etc. — age. A thorough cardiac workup and stress test are prudent and probably the first priorities. Many cardiologists familiar with dive medicine recommend a cardiac stress test targeting a score of 13 metabolic equivalents (METs), while others recommend a minimum of 10 METs. Either level is rigorous exercise. While most diving is relaxing, a strong current, a long surface swim or rescuing a buddy (or oneself) all require a high level of exercise tolerance. Awareness of underlying medical issues is of practical use. The basic aches of arthritis could be confused with decompression sickness, so conservative profiles are recommended for anyone who deals with this issue. Also, diving in locations with reasonable access to medical care is prudent. Anyone can have a medical or diving emergency, and age makes medical emergencies more likely. A minor issue that occurs within reasonable access to medical care can be STEPHEN FRINK STEPHEN FRINK handled easily. The same issue can be much more problematic on a remote island or liveaboard hours or days from medical care. — Frances Smith, EMT-P, DMT Q: I know nitrogen is not metabolized by the body, and I’ve read that tech divers are facing issues with helium bends. Is the size of the molecules relevant? Helium molecules are smaller and lighter than oxygen molecules, while nitrogen molecules are larger. Some people are filling their car tires with nitrogen because it supposedly leaks out of the tire more slowly than air. A: There are times when size matters and times when it is a red herring. This is one of those cases where it’s a little bit of both. Nitrogen is a slightly larger molecule than 54 | SPRING 2016
oxygen (by about 2 percent), but that does not have anything to do with its reactivity in the body. A better analogy would be how wood and steel interact with a magnet. The steel reacts, while the wood does not. A helium molecule, on the other hand, is one-third the size of a nitrogen molecule. Molecule size can make a difference in passing through some barriers, but it is almost certainly not the only factor in uptake and elimination or its nonnarcotic nature relative to nitrogen. Interestingly, while helium is considered a fast gas in terms of exchange, it can cause challenges in decompression, resulting in the need for more buffering of limits based on expectations of exchange speed. You may be hearing more about decompression related to helium in large part because of its increased use by recreational technical divers. Broadening the use sometimes brings out new issues not discovered in more limited traditional use. As I like to say, physiology does not equal math. Physiology is much more dynamic. Seemingly logical ideas, such as size being a critical factor, can be attractive but do not answer the question. Asking questions, though, and having a lifelong interest in learning are critical in getting closer to the elusive truth. By the way, it is not worth paying to fill your tires with nitrogen. — Neal W. Pollock, Ph.D. Q: Why does it seem like the answers I read in Alert Diver or on DAN.org are so conservative? You advise caution for medical issues I would never give a second thought to when participating in other activities such as skiing, tennis, basketball or exercising at the gym. It seems like your organization is afraid for anyone but the healthiest people to dive. A: Many divers have medical conditions and/ or take medications and enjoy diving without any problems. DAN’s role is to provide information based on the available literature and prevailing expert opinions in diving medicine, not to decide who is allowed or prohibited from diving. We advise divers (and potential divers) and their doctors so they can make thoughtful and informed decisions about diving. Sometimes DAN recommends that divers or potential divers be evaluated by a physician who has special training in diving medicine. Hazards exist in the diving environment that are not present in most other recreational activities. If someone playing basketball gets dizzy or short of breath, he or she can easily stop the activity and rest. If a medical emergency arises, emergency medical services are readily available. The underwater world, however, is unforgiving, and problems can increase the risk of drowning. Shortness of breath, for example, does not always resolve with rest while underwater because of the increased resistance involved in breathing through a regulator. It is important to remember that when scuba diving we are using lifesupport equipment to explore an environment not conducive to human survival. — Scott Smith, EMT-P Q:I recently returned home from a two-week liveaboard dive trip. After experiencing some initial motion sickness while adapting to the motion of the boat, I had a wonderful trip. At the end of the trip, however, I felt like the dock was rocking when we disembarked. I was queasy and almost vomited. This feeling continued for nearly a week before resolving. Why did this happen? A: While we cannot say with certainty what caused your symptoms, you may have been suffering from condition that’s known by various names COLIN FIELD/ISTOCKPHOTO.COM ALERTDIVER.COM | 55
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