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“Sharks Are Turning Into Underwater Circus Animals”

Even if food was dangled in a bait box, sharks expect to eat once they reach the scent. If they don’t get food from the bait box, won’t they get frustrated and start poking around? “Frustration is a human emotion, but sharks do demonstrate they’re in an agitated condition when there is an olfactory sense in the water,” says George Burgess, director of Florida Program for Shark Research at the University of Florida. “If you merely tease them with food, it’s like waving candy in front of a baby.”

Burgess credits Abernethy for doing trips away from civilization, but he thinks divers claiming to do shark dives to protect sharks are off-base. “What you’re getting is trained animals used to humans being in the water and used to being fed. We know they’re trained because they arrive before any food is put out. Some boats rev their engines and say, ‘We’re calling in our babies’. Sharks are attracted to the sound, just like Pavlov’s dog, that dinner is coming. They’re the equivalent of underwater circus animals. Their activities are not the behavior of wild sharks but trained sharks.”

In the Bahamas and the Caribbean, unassisted shark sightings by divers are becoming rare because sharks are disappearing. Sharks also have a natural concern over unfamiliar things, especially those near their own size. “Encountering humans is an unusual event for them, so there’s a natural distance out of concern, or respect,” says Burgess. “Once that natural behavior is modified, it’s lost and that’s where problems begin. It’s akin to problems with bears. But dive operators want to keep a lot of sharks in one place for predictability – and deliver a product for paying customers. However, divers are seeing an underwater Disneyland rather than a natural world.”

Scuba Diving Fins

Mares Raptor Fins

The Italian company Mares has always been at the forefront of fin design but it has eschewed the split-fin idea for years. Working with the boffins at Genova University, with their famous motorized underwater test bench, Mares has come up with some designs that have been so good, notably the Mares Plana Avanti Quattro, that they have dominated the market worldwide -- except America, that is. American divers want split fins, so Mares has introduced the Raptor.

It has a slim-looking fin with a blade that has the characteristic split, but the blade is prevented from bending too much at the outer edges by exceedingly strong side bars. Panels of softer compound allow some flex in the center part of the blade that curves dramatically away from the foot-pocket in a fixed downward arc. The foot-pocket itself is incorporated into a sleek, single-piece unit together with the blade so that there are no edges to disrupt the water flow. A single piece of hard plastic goes from the heel to the blade tip and the foot-pocket has inserts of a softer compound to give some grip when standing in the fins.

These use the latest version of the Mares Advanced Buckle System that cantilevers out to allow you to put your foot easily into the foot-pocket and then clams shut to pull the strap tight. You can do these conveniently with the opposing foot, and that means you don’t have to stoop while wearing your tank to do it.

Unfortunately, when it came do undoing the buckles after a dive, I was out of luck. You have to squeeze two opposing little releases together. I was totally unable to free up the buckles, nor could the deckhand who tried to help.

I first used them on a dive around a 350-foot-long wreck in the Red Sea. The Rosalie Moller is 170 feet deep. I sprinted down the line to the stern, then to the bow and back to the line. It took only a few minutes. The two divers I had passed on my way said they saw me go by “like a bullet.” I then gave them to fellow diver, Irishman Damien Joyce, to try on the following dive. He came back beaming. “My goodness, these things are mighty! They go like the clappers when you want to accelerate.”

He summed them up well. Just as it did with the Plana Avanti Quattro, Mares has again come up with a winning design for a fin, this time with a split blade. I would not be surprised to see these adopted for common use by dive guides throughout the world, just as its worthy predecessors from the Genovese manufacturer already have. Scuba Diving Fins

Aileron Fins

These fins have their blades cantilevered away from the line of the foot-pocket by a couple of integrated struts. The idea is that you can walk while wearing them. Secondly, because the blade is away from the turbulence caused by the leg and fin, they perform better than conventional fins. They are available with a slipper-style foot-pocket or an open-heel design with a strap. Both had a foot-pocket reminiscent of a rubber clog.

The question for me was would they provide a boost in performance that would be worth the ridicule I was sure to suffer if I turned up on a liveaboard sporting a pair? The blades seemed similar to those of conventional paddle fins. There were no soft rubber inserts to give lateral flex and provide a scooping effect, and no split to emulate a fastswimming fish. My expectation was that they would be as inefficient as an old-fashioned pair of flippers but I decided to give them a try, armed with an underwater speedometer and a pair of industry-standard Mares Plana Avanti Quattros for comparison.

I made several runs, swimming my heart out with the speedo held in front of me. Each time, I noted the highest speed I could muster, and the Ailerons failed to keep their promise. The best I could manage was a heart-busting 2.4 mph, and that was the best of many runs (always waiting until I was fully rested before giving it another go). In contrast, I achieved an almost effortless 2.85 mph with the Quattros on a single run. Not only that, while finning at the surface with the Ailerons, I splashed more than usual because the fins tended to break the surface.

The only perceived benefit seems to be the ability to walk around easily while wearing them. However, I always say that a diver in the water without fins is endangered -- as is the diver out of the water who wears fins. So why walk about anyhow? Scuba Diving Certification

How Many Divers Get Certified?

In 1988, PADI reported certifying 400,000, but it was clearly an inflated number that included all certifications - e.g., rescue diver - and dual certifications (it was common for people to complete one course, but get cards from two agencies). Bret Gilliam, who founded the training agency TDI/SDI, started the magazine Fathoms and was once the CEO of dive gear manufacturer UWATEC, says that dive agencies routinely blow smoke up people's skirts, and PADI's figures were "far from the truth." No other agencies reported the numbers they certified, but PADI was not the dominant training agency that it is today, so 800,000 new divers a year might have easily been assumed by McAniff.

In 2002, four agencies - PADI, SSI, NAUI and SDI - agreed to share data. They reported certifying 177,000 new divers, but it is unlikely that certifications have dropped 50 percent since PADI's claim. But McAniff's 3.5 million diver guess in 1988 was clearly based on an inflated number, easily three times too high.

Unfortunately, certification data in the future won't be much good.While DEMA's certification audit gets data from four big agencies, there are 10 total and six refuse to play fair. Mark Young says one agency is planning to bail out because of political reasons. "Plus, the numbers they send in are not a complete picture because the agencies themselves question the numbers and how they're gotten." Scuba Diving

When you tell people you meet for the first time that you are a certified PADI (Professional Association of Diving Instructors) scuba diver, their immediate reaction is “Wow. You are? I’m not sure I could do that!” The response is often followed by a barrage of questions indicating curiosity mixed with a touch of apprehension and perhaps a fair amount of misinformation.

As an active recreational pastime goes, Scuba diving is probably one of the easiest to learn, there are only three basic skills , floating, kicking and breathing, there is more to it than that, but if you can breathe through your mouth, then the chances are you can learn to scuba dive.

The necessary skills are not tough for most people to master, during the PADI Open Water course, you’re introduced to knowledge development and safe diving practices. You rehearse equipment-related skills in a controlled water setting until you feel comfortable, as well as practice what to do if things don’t go as planned.

The bulky scuba gear worn by many divers may seem intimidating, but learning to use it is straightforward. If you’ve snorkeled, you’re already familiar with the mask, snorkel and fins.

The scuba unit consists of an air cylinder containing compressed breathing gas, buoyancy compensator (BC) jacket to help you float on the surface and maintain your desired depth underwater, and a regulator for you to breathe through. The exposure protection ( wet suit ) keeps you warm when diving in cool-water environments.

You don’t need to be a strong swimmer or an athlete to scuba dive, but some degree of comfort in the water most certainly helps. Even if you enter scuba training with less than total confidence in your water skills, by the time you receive your first certification card, your comfort level will be greatly increased.

If you are motivated to step through the door into an exciting new world, then the diving experience will prove both energizing and confidence-building. Scuba Diving and Decompression Sickness

Also known as The Bends and Caisson Disease, Decompression Sickness is an illness that can affect divers or other people (such as miners) who are in a situation that involves pressure rapidly decreasing around the body.

DCS, as it is commonly know, is caused by a build up of nitrogen bubbles in the body. When we breathe, approximately 79 of the air we're breathing is nitrogen. As we descend in water, the pressure around our bodies increases, causing nitrogen to be absorbed into our body tissues. This is not actually harmful and it's quite possible for the body to continue to absorb nitrogen until it reaches a point called saturation, which is the point at which the pressure in the tissues equals the surrounding pressure.

The problem arises when this pressure needs to be released. In order to release the nitrogen slowly from the body, a diver must ascend slowly and carry out decompression stops if necessary - this allows the nitrogen to slowly seep out of the body tissues and either immediately revert to being a gas or to become tiny harmless bubbles which will eventually become revert to gas. This process is called "Off-gassing" and is normally carried out through the lungs.

If a diver ascends too fast and the nitrogen escapes the body tissue too quickly it becomes bubbles in the body and this leads to Decompression Sickness. The bubbles must normally be on the arterial side of the circulatory system to be harmful - they are usually harmless on the venous side.

 

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