Tag Archive
Stress in Diving
I don't want to participate in any sport in which my species is not at the top of the food chain. Ken Fonte Stress in diving is probably the central problem in the accidents and resulting injuries and fatalitiesthat occur to divers . . . Art Bachrach and Glen Egstrom STRESS Many divers do not seem to place traditional activities in the context of stress-inducing scenarios. Diving is supposed to be fun, right? The following passage is excerpted from Bachrach and Egstrom's (1987) Stress and Performance in Diving: "We will cover your nose and eyes with a rubber and glass cup that will give you tunnel vision and prevent breathing through your nose. A snorkel which is partially filled with water will increase breathing resistance, especially when you work harder. A rubber suit will increase your surface area and your buoyancy while creating a restriction over each of the body's joints. (A partial adjustment will be made by fastening 15-20 pounds (6.8-9.1 kg) of lead to your waist.) Fins for your feet will make walking more difficult and require more energy when swimming. A buoyancy compensation device will provide additional drag, especially when it is inflated to increase your buoyancy. Approximately 40-50 pounds (18.2-22.7 kg) of steel or aluminum will be fixed between your shoulder blades by means of a backpack with a series of straps and buckles, which will terminate somewhere under the buoyancy compensator near the weight belt buckle. A regulator with various and sundry hoses and gauges will be attached to the tank and will cause you to breathe against an added resistance both during inhalation and exhalation. Various other items, such as knives, gauges, goody bags, cameras, spear guns, gloves, hoods and booties will be added for your comfort and convenience." These learned authors (by this... More »
The Use of Trial Exhibits by Expert Witnesses in Litigation
I did an article for Undercurrent called "Anatomy of A Diving Lawsuit" in 2009 that dealt with the analysis of a specific single case and trial that I worked on as the defense maritime and diving expert. This involved the disappearance of two divers at Cocos Island, nearly 500 miles offshore of Costa Rica. This is follow up piece that expands the narrative. A key thing at trial is being able to use exhibits during testimony to help the jury understand complicated facts, theories, and the geography on an area where an accident or fatality has occurred. It's a complicated process and most trials end up being won by primary expert witnesses during their live testimony. Doing the "grunt" work on the files is fairly routine but takes time and a bit of careful strategy in coming up with a defense posture that can play effectively to a judge or jury. But there is nothing like the pressure of a live deposition or trial wherein the absolute necessity for extemporaneous and calculated quick thought plays such a vital role. As an expert witness, it is impossible to fully anticipate where the cross-examination will go, what ploys are attempted by opposing counsel, what tactic to deceive you about the actual evidence or prior testimony may be taken, etc. It is a very stressful role to play as you must not only protect the defendants' conduct with sometimes very extemporaneous responses, but also remember to maintain control and speak to the jury as a credible, likable, and professional witness in whom they should place their trust to explain the complicated facts and nuance so they choose to favor your opinion over that of the opposition. It is an arena that few people do well in and requires a tremendous degree of control and... More »
Tanks and Weights
Well - maybe it shouldn't have taken me by surprise. But it did. A communicating New England area dive shop told me, "It's OK to sell integrated weights BCs because divers don't drop their weight-belts anyway." An honest peddler - at least honest in describing his outlook. Almost as bad as, "I have insurance for that." Under the banner of, "It's our livelihood," we have dangerous junk being sold because "...they don't drop their weight-belts anyway..." (that really floored me), "Sell the aluminums 'cause we can "crack fail" them in a couple of years." "It's a 'low-flow' regulator - they put them on pony bottles." Someone tried that one on me. Imagine? Putting what he classed as a "low flow" regulator on a "pony bottle" justified its existence in some way or other. I couldn't make the connection - but - if the effen thing was for making an escape to the surface, why put all your marbles into a "low flow" regulator? The last people who should be passing their hands over scuba cylinders are people who sell them. In this economy, the lure is too great. The DOT almost prohibits such a close association. TITLE 49 CFR 2010 (107.803):: "...No independent inspection agency...may have a financial involvement with any entity that manufactures cylinders ...except as an independent inspector (such as myself ). Fred Calhoun doesn't sell cylinders, he is "qualified" to inspect, and he inspects. His customers often visit dive shops for air fills, and are subject to a litany of questions implying that maybe there's something wrong with the cylinder, or the person who did the inspection and affixed the EOI sticker. I'm qualified (I don't sell the things). I have a wallet c-card that has my name on it - says I'm qualified. I wrote the book SCUBA CYLINDERS... More »
A response to “A Divemaster’s thoughtful Rant”
I am glad to see that I am in the good company of Bret Gilliam in wishing to respond to the anonymous JD (are you scared to say who you are, JD?) with a few home truths about divemasters, gleaned from my nearly 50 years of scuba diving. I have experienced all of the following behaviours from professional DMs, some many times: DMs with limited experience, but who think they know it all and treat you like a simpleton DMs who lack flexibility of approach to their job- the 'do-it-my-way or not at all' type DMs who apply silly limitations to one's dive time and depth so one returns to the surface with over half a tank left; some really stupid behaviours in this category DMs who think they are Ian Thorpe & swim like hell, expecting everyone to keep up, thus depriving clients of the opportunity of having a real look around DMs who allocate divers to buddy pairs for their dive, but then insists that everyone start to ascend when the first diver has used their air to 100 bar DMs with no ability to cope with a group with mixed diving skills/experience DMs who do not know the environment they are guiding in DMs who just float around looking bored and making no attempt to look for critters for their clients DMs who use horns, beeps or tap their tank constantly throughout the dive as though they were in the middle of the Paris rush hour traffic DMs who are demonstrably anxious DMs who run out of air before their clients do DMs who give you a harangue at the dive briefing about care of the coral, then proceed to knock the hell out of it themselves because they have no idea where their fins are or who... More »
Nitrox and Other Gases
A reader of Britain’s Diver Magazine recently wrote to me complaining that I had admitted in print to using independent twin tanks, one tank with air (MOD 182 feet at 1.4 bar ppO2) and one tank with nitrox 32 (MOD 108 feet) for a dive to 165 feet. He congratulates me on effectively using a single tank of air at 165 feet and asks what I would have done had my regulator failed? Well, I would have used the one on the other tank! Bear in mind, regulators and other equipment subject to high gas pressures usually fail when that pressure is at its highest. That is to say at the very beginning of a dive, not half way through it, unless it's caused by icing. In a history of a great many dives I have yet to experience a true failure in seawater other than within the first moments of turning a tank on. He goes on to ask what I should tell newly trained divers about going to 165 feet with only one tank. I answer that newly trained divers should stick to the depth limits of their certification and that if a PADI Open Water diver can go to 60 feet on a single tank, I believe a suitably trained and experienced diver with a twinset can go 60 feet below the MOD of the gas in his second tank providing he is breathing a suitable supply of gas in his first. Even then, the ppO2 limit of 1.4 bar is a limit currently set by training agencies with an eye on litigation. When we started using nitrox around fifteen years ago, we all used at least 1.6 bar as a limit. A limit of 1.6 bar ppO2 gives an MOD for nitrox 32 of 130 feet, so at 165... More »
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