about sharks in general.
First, most shark attacks, even those well publicized recent ones from the Gulf of Mexico and the East Coast are cases of mistaken identity. People are not part of the regular diet of these predatory animals. In fact, in most areas where seals are uncommon, we are simply too big for them to even consider.
In areas where sharks feed on seals and other big critters, surfers on boards are most often the ones hit. A surfer on a board silhouetted at the surface looks remarkably like a seal to a shark looking up. The common feeding pass for a large Tiger or a White in these circumstances is not a "bump", but a rapid vertical ascent right under the target animal. The shark never really sees what it hits and the surfer often never knows what hit him. Not much you could do about that, I would venture to guess.
In areas like the Gulf, it is usually small to medium sharks feeding nearshore in murky water that make the hits on people. That's why in these areas you often read of someone getting bitten, then released, losing some large but not fatally large, chunk of flesh.
In the case of what happened in Pensacola, this was a large shark, but not one big enough to consider a large child as a "normal" meal. It was a bite of opportunity, the shark, probably feeding on small fish in the murky water, got ahold of the boy and tasting blood, an then did not wish to let go. I don't think it was predatory behavior specfically directed at the child. When we are at the beach, I don't let my kids play in the surf when I can see large schools of fish being agitated by something feeding on them. While this usually means there are jacks feeding there, I wait until things calm down.
Unfortunately, Florida is a political state with a large population of people who believe in "regulatory lifestyles". If something bad happens, blame is usually assessed, rightly or wrongly and then, someone cries out, "there ought be a law".
After a couple of these well publicized incidents, the resulting action was a moronic ban on "shark dives".
Despite myths to the contrary, no shark attacks in Florida waters have been associated with shark dives. No shark dives occured anywhere at ANY TIME near where the attacks took place.
While it is concievable that shark behaviors, like those of HIGHER ORDER mammals like bears, are alterable by familiarity with humans, there has been no documentable associating of human attacks directly linked to these sorts of diving excursions.
What human behaviors HAVE been associated with attacks? Well, duh.....
Widespread shark "chumming" as practiced by Florida coastal fishing is one very likely culprit. In fact, at least two attacks I know of occured in areas where fishermen AT THAT TIME were actively engaged in drawing sharks over a large area using blood baits. Widespread chumming, unlike the more controlled feeds around "chumsicles" brings sharks into an aggressive feeding state over a large area. Add murky water to the mix, which shark dives obviously avoid, and you have a recipe for a shark attack. (chumsicles are not bloody concoctions designed to invoke a frenzy, but baits designed to bring the sharks to them in a more controlled fashion).
Did anyone cry out for a ban on shark fishing after the attacks? Heck no. Fishermen are more numerous and have greater political stroke than divers. Besides, fishermen kill sharks, not coddle them.
I have been diving for 25 years. During my early years I did a lot of spearfishing, and later, I made dives specficically to observe and photograph sharks. I have been in schools of hammerheads and silkies so thick they filled my liquid "sky". I have been approached by bull sharks and once, by a Tiger.
Not once have I felt that I was in imminent danger. Have I been nervous on occasion? Yes. I'm not an idiot. Schooling sharks are known to be a non-threat, but sharks are primitive animals --they respond to immediate stimuli and follow their own rules. I've watched silkies biting each other in an aggressive, but non-feeding behavior while they schooled around an offshore oil rig. I inadvertantly drifted into their school while taking photos and did not notice that they quit circling the rig we were on, but started circling me. I wasn't afraid, but I did think it odd and it seemed like a good idea for me to back to the relative safety of the rig. Was I likely to be attacked? I don't think so, but prudence was the better part of valor (jeesh. or something like that...)
While spearfishing once or twice I observed the "jerky hunch backed" stance of an aggressive shark and I worried that he would mistake me for lunch--or as a big fish that was competing for his lunch. But, I knew that such an attack was not predisposed, but likely the result of too much stimulation from what I was doing. I left my fish for the shark and left the water. No big deal.
Although some larger species, like the Great White, may "stalk" prey over the short term, most of these animals are opportunistic. They don't "plan" a hunt. They just hunt.
What would I do if a shark "bumped" me in a pass or directed aggressive behavior at me? That depends, I guess. Assuming that I would have some warning......If I was spearfishing, I'd distance myself from the stimulation. Let him have my fish.
If I was taking photos, I'd turn off my strobe (in case it was leaking a current..which is a stimulus) and I'd use it as a barrier. I would not "attack", but I would watch the animal as best I could. Lacking a camera, I might consider removing my BC/tank and using it as a barrier, as long as I was wearing enough weights to keep me under control if I were to lose my rig.
I wouldn't surface unless I was right under the boat or out of air, but I might slowly ascend to where I had more options. Even a few feet under water you have the ability to observe the shark more easily, maneuver for protection and to swim more smoothly than you would swimming at the surface.
Cavitation of water at the surface, jerky movements or thrashing would be things I would most avoid.
But....Sharks are the least of our worries. I love seeing them on a dive and always feel they add to the experience. On my last trip offshore Texas, I saw "spinners" for the first time up close. They were magnificant in their leaps from the water and were a testament to the idea that sharks are both graceful and agile creatures to be admired.
