The Great Hammerhead Sharks of Bimini are something very special… Sphyrna mokarran are large, powerful and generally solitary sharks, and encounters with them in the wild are usually fleeting. They are also now Critically Endangered, having suffered major population declines as a result of fishing pressure and the international trade in shark fins.
But every winter, a number of these remarkable sharks gather in the waters off South Bimini in the Bahamas. Creating one of the world’s most reliable opportunities to encounter them at close range.
My first close encounter with a Great Hammerhead was actually in the Solomon Islands. It was brief, but memorable.
There is something about hammerheads that makes an immediate impression. The extraordinary width of the head, the tall, sickle-shaped dorsal fin and the slightly sinuous way the animal moves through the water.
The Bimini experience is something else entirely. Here, the sharks can approach close enough that you can study them in detail, watch their behaviour and, for an underwater photographer, get the sort of images that are almost impossible to obtain during a fleeting encounter in the open ocean.
Why South Bimini?
The Bimini Islands sit on the western edge of the Great Bahama Bank, only about 80–85 km from the coast of Florida. To the north, south and east, the shallow waters of the bank extend across a huge area. While immediately to the west of Bimini the seabed drops away towards much deeper water.
The islands are therefore positioned at an interesting boundary between the shallow Bahama Banks and the deeper waters of the western Atlantic. The Gulf Stream also passes close to Bimini as it flows northwards through the Florida Straits. The combination of shallow banks, deep water, mangroves, seagrass and strong oceanic currents creates a highly productive marine environment.
That productivity supports an impressive range of marine life, including the rays, fish and other prey on which larger predators depend. But there is another important reason Bimini became such a significant location for shark research.
The Shark Lab and the Discovery
South Bimini is home to the Bimini Biological Field Station, better known as the Shark Lab. Founded by Dr Samuel Gruber, the field station has been studying sharks and rays around Bimini for decades. With the resident Lemon Shark population being one of the original reasons the location was chosen for research.
The Shark Lab became aware of the reliable seasonal presence of Great Hammerheads around Bimini in the early 2000s. And, for a number of years the location remained relatively little known outside the research community.
That eventually changed… Word spread, and South Bimini developed into one of the world’s best-known destinations for close encounters with Great Hammerhead Sharks.
The sharks are not simply passing visitors, either. Research has shown that some individuals display strong seasonal residency and site fidelity, returning to Bimini during the winter months. That seasonal pattern is one of the reasons the encounters can be so reliable.
Face to Face…
Any encounter with a large animal underwater is an incredible mixture of fear and excitement.
And it is usually at its most intense just before entering the water for the first time. You can read the briefings, study the photographs and listen to people who have done it before.
But when push comes to shove and it is time to get in the water, the heart rate inevitably goes up a little.
The first thing that strikes you about a Great Hammerhead is its sheer presence. Like a fashion model walking onto a catwalk, they seem to make an entrance.
The shark approaches from the blue, its distinctive head sweeping slowly from side to side. The movement gives the rest of the body an almost snake-like quality, while the tall dorsal fin and robust body make it unmistakable.
And then it is suddenly very close.
The Bimini encounters are conducted in relatively shallow water over sand, close to the western side of South Bimini.
The sharks are attracted to the site using food provisioning, with divers positioned around a bait box and a feeder controlling the presentation of the food. It is a carefully managed encounter, but there is no mistaking the fact that the animals are wild. And that becomes increasingly obvious as the day progresses.
Great Hammerhead Sharks of Bimini – Feeding Time
The mechanics of the feeding are relatively simple. A Great Hammerhead approaches the feeder and sees the offered piece of fish. At the last moment, the bait is flicked to one side, directing the shark towards one of the photographers waiting on either side. The shark follows the bait, turns and continues towards it.
But there is an amusing and slightly intimidating complication. Because once the shark turns its head, the bait can effectively disappear beneath that extraordinary hammer-shaped cephalofoil. And so the shark then chomps around until it finds the food. So, if it’s your turn to be positioned next to the bait box, that is happening just above you… At which point, you become very grateful that your camera housing is made of aluminium!
For the underwater photographer, however, it is an extraordinary opportunity. The sharks are close, the water is shallow and the encounters can be repeated. You can concentrate on composition rather than simply trying to get a record shot before the animal disappears into the blue.
And the Great Hammerhead is a superb photographic subject. That broad head creates an instantly recognisable silhouette, while the shark’s approach can produce powerful head-on images that are simply impossible during a fleeting open-water encounter.
Photographing the Great Hammerhead Sharks of Bimini
For me, one of the attractions of Bimini is the opportunity to really work with the animal photographically. A fleeting encounter with a Great Hammerhead usually means reacting quickly. Often with the shark moving away before you have had time to establish a composition.
Bimini is different… The sharks repeatedly approach the feeding station, giving photographers time to anticipate the movement and position themselves.
The shallow water also helps enormously. There is plenty of ambient light, and the combination of blue water and the shark’s powerful form can produce very clean images. A wide-angle lens is the obvious choice, particularly when a shark comes directly towards you.
But the most important thing is not the equipment. It is getting low, anticipating the shark’s approach and being ready when that enormous head suddenly fills the frame.
And after a couple of days something rather strange happens and the initial excitement begins to dissipate. The sharks arrive, they approach the feeder and they take their food (snack…). Then they turn and disappear and, after a while, it starts to feel almost predictable and a little like a petting zoo.
And then you do the night dive.
The Great Hammerhead Sharks of Bimini – When the Sun Goes Down…
The night dive was the part of the experience that really brought home to me that we were truly interacting with wild animals.
We began in the late afternoon and continued as the light faded into dusk and eventually darkness. The same basic feeding routine continued, but the atmosphere changed completely as the light faded.
The Great Hammerheads became much more active. And, instead of slowly approaching along the bottom, they came in faster and at chest height. Their body language was completely different and there was no mistaking the change!
During the daylight dives it had become easy to become comfortable with the routine. After dark, that comfort disappeared completely and although I did not feel that I was in immediate danger. I was acutely conscious that these were wild animals and that we were in their environment.
And then there were the Bull Sharks.
The Bull Sharks
We had been warned about Bull Sharks before the night dive, but during the daytime encounters I don’t remember seeing many of them.
As dusk arrived, that changed. We could see Bull Sharks cruising around the feeding area in the distance.
Then they began coming closer… The feeders would bang on the bait box to discourage them, but they would soon return.
As darkness fell, keeping track of where the Bull Sharks were became increasingly difficult.
Which was the point when I started thinking about what might be happening behind me as well as in front.
I have never been a great fan of Bull Sharks, and for me they created considerably more psychological tension than the Great Hammerheads.
The instructions for leaving the water were therefore taken very seriously.
Only a couple of people were allowed at the surface behind the boat at any one time, and we were told to get out of the water quickly. When my turn came, I produced what can only be described as an Olympic performance getting back into the boat. The relief was considerable…
The Ethics of Shark Feeding
Feeding, or “provisioning”wild sharks for tourism is quite contentious. The argument against it is straightforward in that regular food rewards can alter animal behaviour, concentrate animals at particular locations and potentially affect their normal feeding patterns. In the case of large and highly mobile predators, those changes could have significant consequences beyond the individual sharks involved.
The counterargument is that shark tourism can generate substantial economic value while giving people an opportunity to see these animals as living creatures rather than as trophies or threats.
A 2021 study of Great Hammerheads of Bimini provisioning site examined 104 dives and identified 28 individual sharks. The researchers found that some sharks showed strong site fidelity and repeatedly attended the feeding dives. With some individuals spending more than two hours at the site and consuming enough provisioned food to meet their estimated daily energy requirements.
The same study also concluded that it was currently not possible to determine how provisioning impacted the broader ecological role of the sharks or the overall Bimini ecosystem. The researchers also found evidence that the sharks’ annual migration patterns were not necessarily disrupted, with most seasonally resident sharks leaving Bimini as summer approached.
My non-scientific opinion (for what it is worth…) is based on in-water exposure to sharks of numerous different types of sharks in many different locations. Overwhelmingly, that experience has shown me that the only way to get close enough to medium and large sharks is through some form of provisioning.
Neither have I ever seen any significant indication of permanent behavourial change. Yes, the sharks are attracted by the smell of food in the water, but that’s how sharks behave as they need to eat.
Why Great Hammerheads Matter
The Great Hammerhead is a very impressive photographic subject. It”s also one of the world’s most threatened large sharks and currently assessed as Critically Endangered on the IUCN Red List. With overfishing, bycatch and the value of its fins among the major threats.
That dire status is compounded by its slow growth and reproductive characteristics. Which make recovery from population depletion difficult.
The Bahamas provides an important contrast to that global situation. In 2011, the country introduced regulations prohibiting the possession, fishing for and landing of sharks and shark parts in Bahamian waters. That protection is particularly important for a species such as the Great Hammerhead, which is highly vulnerable to fishing mortality. And it is one of the reasons that places such as Bimini are so valuable.
The opportunity to see Great Hammerhead Sharks alive, healthy and behaving naturally in their environment is truly a special thing and why Bimini is such a special place!
Great Hammerhead Sharks of Bimini
What makes South Bimini special is not simply that Great Hammerheads can be seen there. It is the combination of reliability, proximity and the quality of the encounters.
These are large, powerful and critically endangered sharks that are normally difficult to observe.
At Bimini, they can come close enough for you to see the detail in their eyes, watch the distinctive movement of that enormous head and appreciate just how impressive the animal really is.
The daytime encounters provide extraordinary photographic opportunities. The night dive provides something else entirely and that experience is perhaps the most enduring memory I have of Bimini.
