Swimming with sharks

They've been a menace all summer. Every time you enter their environment you put your life at risk. Nonsense, says Simon Rogerson, who explodes a myth or two about the oceans' top predators ? and those who dive with them

We live in an enlightened age in which large predators such as tigers are revered and protected – but sharks are still playing the villain's role

We live in an enlightened age in which large predators such as tigers are revered and protected – but sharks are still playing the villain's role. This summer has seen a wave of anti-shark hysteria on the same scale as was generated by the release of Steven Spielberg's Jaws in 1975. This time the cause is a series of unconnected attacks off Florida and the Bahamas, and the finger of blame is being pointed not just at sharks, but at shark divers. As recently as 10 years ago, the few divers who deliberately entered the water with sharks were widely denounced as mindless thrill-seekers, risking their lives in the name of machismo. Then the rest of the scuba-diving world gradually realised that shark divers were not being routinely devoured, and more often than not returned safely with stories of awe-inspiring encounters. Shark diving has entered the mainstream, and is now big business. But still the misleading stories persist...

The myths

The myth: To dive with sharks is the sole preserve of muscle-bound adrenalin junkies.
The truth: In most cases, shark diving is no more physically demanding than normal scuba-diving. Today's shark enthusiasts are normal people who have a particular appreciation of the ocean's predators. Seeing your first shark is an unforgettable experience and, yes, there is a frisson of danger. But the shark is far more scared of the diver.

The myth:Feeding alters the predators' natural behaviour. They come to expect food from people, and when they don't get it they attack swimmers instead.
The truth: Shark expert Jeremy Stafford-Deitsch says there is no evidence of any links between feeding and the recent attacks on surfers in Florida which sparked the current debate. We now know that the surfers saw large tiger and bull sharks feeding on a school of fish in the shallows, and still tried to paddle out to the surf despite this intense feeding activity. "The fact that no one was actually killed shows just how hard it is to get attacked by a shark," Stafford-Deitsch says. Nevertheless, there is evidence that hand-feeding can alter the way a shark responds to divers, and the Shark Trust recommend lowering a frozen block of fish parts into the water. The sharks bite pieces off as the "chumsicle" melts, and the divers are merely regarded as other predators.

The myth: All sharks are predators, and when people enter the water they are little more than shark bait.
The truth: Of the hundreds of shark species, few present a genuine threat. Of these, the great white, tiger, bull and oceanic white-tip are probably the most dangerous. However, they are rarely seen, and account for very few deaths. Even these sharks tend to be wary of man; attacks are usually the result of mistaken identity. In the case of great whites, we don't have enough body-fat to be worth eating, but a surfer on the surface looks pretty much like an injured seal or dolphin, so the shark sometimes takes an exploratory bite.

The myth: Sharks are unpredictable, aggressive and attack without warning.
The truth: The shark species most commonly encountered by divers display unease or aggression by swimming in jerky, exaggerated movements. If a reef shark is moving slowly and gracefully, chances are that it is not likely to present a threat. The caveat with all shark dives, though, is that these are large, wild animals, and should be treated with respect at all times.

The myth: Shark divers are only safe if they use chain-mail suits or cages.
The truth: Some divers do wear chain-mail suits, but they are generally group leaders directly feeding sharks or in charge of safety. Film-makers who use extra bait to get close-up footage of feeding sharks sometimes wear these suits. Cages are used when a large shark has been attracted by chumming (pouring fish blood into the water) and has shifted into feeding mode.

The sharks

Reef white-tip shark
This is the shark that most neophyte divers see first. Commonly seen on shallow reefs from the Red Sea to Central America, they grow to about two metres. Easily identified by their thin bodies and white markings on the fins, they are extremely placid and allow divers to approach to within a few feet.
Best seen at: Sipadan Island, Sabah, Malaysia.

Caribbean reef shark
Sleek, powerful predators, they grow to between two and three metres, and can be identified by their blunt snouts and streamlined bodies. At shark feeds, they mostly ignore divers – but stay away from the "zone of competition" around the bait and cover up pasty white skin (which can be mistaken for fish flesh) with wetsuit, hood and gloves.
Best seen at: Walkers Cay, northern Bahamas.

Great white shark
The largest of the predatory sharks ranges across the world's temperate seas, but is often seen off South Australia and South Africa, where it is protected. White sharks grow to six metres, and investigate objects of interest by "mouthing" them. This habit, coupled with their size (think minibus) and power, means they can only be safely viewed from a cage.
Best seen at: Dyer Island, South Africa.

Bull shark

This species is unfairly characterised as a relentless man-eater. Thickset and powerful, they occur in inshore tropical and subtropical waters worldwide (they have also been found more than 1,000 miles up the Amazon). They should be treated with extreme caution, but can be surprisingly placid when not feeding.
Best seen at: Walkers Cay, Bahamas.

Sand tiger shark
The sand tiger shark (main picture) will generally allow divers to approach to within a few feet. They grow to more than three metres, yet the protruding teeth are no threat to divers, but have evolved to help the shark to feed on medium-sized fish. They can stay motionless in the water by swallowing surface air.
Best seen at: Aliwal Shoal, South Africa.

Hammerhead shark
Although there are several sub-species, divers are most likely to encounter the scalloped hammerhead, which reaches four metres. In the Eastern Pacific, they can be seen in schools made up of hundreds of sharks. These sharks are shy, and offer no threat to divers. To get close to hammerheads, find a group of accompanying barberfish, which peck parasites from the sharks' body. Distracted by this process, hammerheads can be easily approached.
Best seen at: Cocos Island, Costa Rica.

Whale shark
The biggest fish in the sea, it grows to a staggering 12 metres and feeds exclusively on zooplankton. An encounter with one of these filter-feeding giants is the ultimate underwater experience. They occur in warm waters worldwide, but are increasingly rare because of a recent Taiwanese fad for whale-shark meat. They are sometimes curious and approach divers – to keep them interested, swim calmly and keep your hands to yourself.
Best seen at: Ningaloo Reef, Western Australia.

Next week: training with the Great Britain team pursuit cycling squad