Tiger Sharks

There are a number of authors who describe tiger sharks as one of the most dangerous marine species. Ralf M. Hennemann, in his book Sharks and Rays of the World, says of these animals, “Without a doubt, the tiger shark is one of the most dangerous sharks in existence. Its large size and opportunistic feeding habits make underwater encounters with this animal a serious threat.” The first time I read this, I couldn't help but think how exciting it would be to dive alongside one of these sharks, which can grow to be larger than the great white shark and have one of the most powerful jaws in the animal kingdom, capable of easily crushing the shell of a sea turtle. On the other hand, our years of experience diving with all types of sharks has taught us that, despite being potentially dangerous, most marine animals are not aggressive toward divers, as long as they observe a few "key" rules that prevent confusion, excite the animal, or make it feel in danger.

Although the tiger shark (Galeocerdo cuvier) has a circumtropical distribution, it's not an easy species to locate. Fortunately, we had contact with Jim Abernethy, an American shark enthusiast who had provided technical support for tiger shark projects for National Geographic, BBC Wildlife, Animal Planet, and the Discovery Channel. His years of experience could guarantee safety in this type of work, and location would be the decisive factor in the success of the expedition.

After choosing the ideal time (due to the water temperature) and several weeks of preparation, we began our journey to Florida, from where we would set sail north of Grand Bahama, in search not only of the tiger shark but also of other equally charismatic species such as the great hammerhead shark (Sphyrna mokarran), which can grow to over 5 meters in length, the bull shark (Carcharinus leucas), and the lemon shark (Negaprion brevirostris). To locate these species, in addition to allowing us to visit their habitats, we also had to attract their attention. To this end, Jim had equipped his boat with a large tank in the bow, loaded with fish, through which water circulates and is then returned to the sea. 24 hours a day, the "perfumed" liquid would be detected by any shark within several kilometers. The truth is that after a full night of sailing, the method yielded its first results, and the light of the new day allowed us to discover numerous fins surrounding the boat.

Despite sharks' bad reputation, the truth is that most of them are shy animals, and the mere presence of divers in the water, especially in remote areas where they're not very accustomed to seeing humans, can be more than enough to make them shy away. To prevent their escape, the solution is to give them something tempting to overcome their shyness, and this is achieved with a bunch of submerged boxes full of fish. The intention isn't to get them to eat it, but rather to get them to smell it and their instinct to stay where we would dive. On the other hand, the bait could trigger aggressive behavior, something we weren't aiming for; to control this situation, bled fish were used at all times, since the presence of blood in the water would be a strong stimulant, and consequently we could lose control of the situation.

No matter how much you've dived with sharks, the moment you jump into the water is still unnerving, especially when several dozen sharks surround the entry point. Most of the specimens gathered on the surface were lemon and Caribbean reef sharks, species that tend to work more in groups, and whose nervous activity tends to attract other larger and solitary predators, such as the tiger shark. The selected sites, with the exception of a few very specific ones, were no deeper than 6 meters, and the bottom was dominated by sand, dotted with a few gorgonians and small blocks of coral. This is a habitat favored by sharks, where they can find rays and other flatfish—half-buried in the sand—and which, thanks to the electroreceptors located on their snouts (ampullae of Lorenzini), they can easily detect and capture. The clarity of the seabed, combined with the clean waters and the penetrating rays of the sun, offered us a magnificent spectacle, where we could simply contemplate dozens of sharks in all directions. Any photographer will understand the pleasure of working with a wide-angle lens at 1/250 speed and apertures of f/16…a dream come true.

The traditional curiosity of the reef sharks was far outweighed by the audacity of the large lemon sharks, animals measuring over 2 m, which were everywhere and we literally had to shake them off to establish a working distance. Despite their calm demeanor, the bait and their impressive teeth made it clear at all times that this was no game, and to avoid mishaps, we had to take some precautionary measures. Sharks have a keen sense of smell and other highly developed sensory organs, but they are not very intelligent animals, and their eyesight is not their best feature, so they could mistake us—at certain times of high activity and large numbers of specimens—for the bait inside the boxes. Dead fish are usually light and pale in color, so we had to stay away from any misleading colors. Wetsuits, fins, and vests that were primarily black (or dark blue) would transform us into "objects" diametrically opposed to what they were looking for. Completing our gear with a black hood and gloves (essential) would guarantee our camouflage, only betrayed by the brightness of our cameras and the "pristine white" of the flash diffusers, something that confirmed on numerous occasions that light colors attract them, and a lot.

As a daily routine, after the first encounters with the "small" sharks, the main guests began to arrive: the tiger sharks. The excellent visibility gave us the opportunity to spot them 30 or 40 meters away, advancing directly, with a slow, sinuous movement, very close to the bottom. The first time you meet the gaze of a tiger shark, with its piercing black eyes, you realize that the situation is very different from any other you've experienced before, comparable only to an encounter with a great white shark. With other sharks, you notice a certain distrust, but the tiger shark dominates the situation and advances directly toward you, clearly trying to determine who this strange visitor is. For an inexperienced person, this behavior could be classified as an attack, but Jim had already warned us, making it clear how we were to behave: stand up to it and stop it.

The truth is that "standing up" to a shark twice your size sounds like madness, and despite the false protection offered by hiding behind the camera, the first encounter is a real adrenaline rush. Fortunately, the system worked in every case: the tiger sought to establish physical contact, its way of exploring the unknown. However, by standing firm and stopping it with an obstacle, the gigantic tiger seemed to lose interest in us for a while, remaining calm in the area until curiosity prompted it to begin stalking us. In our case, the camera was the barrier, the obstacle we placed between the shark and us. Other members of the expedition—not photographers—had a stick, not to hit it (that would be a very, very bad idea), but simply to block its advance. Occasionally, the tigers' audacity leads them to grab the cameras in their large mouths and carry them away, but luckily, after seeing that metal isn't very appetizing, they drop it a few meters away.

From morning to night, every day, the activity with tiger, lemon, and reef sharks was nonstop. Places like Tiger Beach, Purple Planch, Turtle Grass, Ginormous, El Dorado, and Hamertime offered us exceptional encounters and experiences, and at all times, the experienced staff provided us with a safety cover that allowed us to work as we never could have imagined. Although we had at times had very fleeting encounters with giant hammerheads, especially at El Dorado, we still had one last stage to complete the expedition. From the northern Bahamas, we headed south toward Andros Island, stopping in the middle of nowhere at a very special place known as End of the Map, with one clear objective: bull and mokarran sharks.

Unlike most of the previous dives, this dive would be conducted at over 30 meters deep, with the goal of photographing bull sharks. After leaving several boxes of bait on the bottom for almost an hour, we began the descent to encounter a group of robust bull sharks, a fearsome, highly nervous species known for causing numerous attacks on swimmers. This shark should not be confused with the other bull shark (Carcharias taurus), also known as the sand tiger shark or ragged shark, very popular in North Carolina (USA), southeastern Australia, and Aliwal Shoal (South Africa), where our bull shark (Carcharinus leucas) is known as the Zambezi shark.

This dive was very stressful, with the animals clearly becoming excited, even breaking the fish boxes. Despite everything, good teamwork "covering each other's backs" allowed us to enjoy ourselves and work as we had in previous days. And after this high-tension dive, close to the surface, the second guest awaited us: the great hammerhead shark, or mokarran. Despite its size, it proved to be the most elusive and shy of all, and we had to resort to using fresh fish to get it to close the distance and come within range of our cameras. These encounters were fleeting, but they left us with fond memories and a strong desire to return.

After a week of exclusively shark diving, the outcome of this expedition was very positive. Each day of diving was different and better than the last, with experiences truly unimaginable before the trip began. For all this, we must highlight the role played by the crew, both underwater and on the surface, without whom this work would have been literally impossible.