Shark Blog May 2023

by Nigel Marsh

My first ever shark feed was on an un-named reef on Australia’s Great Barrier Reef, way back in 1986. Diving from the old Mike Ball liveaboard Watersport, well before the days of Spoilsport, I wasn’t the only virgin shark feed diver on board as none of the crew had ever done a shark feed before. Although excited, I rated their chances of success very slim, and figured if a shark did show up it would take at least half an hour to appear on the scene. So my buddy, Ian, and I enjoyed afternoon tea, while everyone else eagerly jumped in the water.

We finally entered the water forty minutes after the other keen divers only to find them all sitting on the bottom and looking very bored, not a shark in sight, not even a white-tip reef shark. Rather than join the tedious and possibly pointless wait, Ian and I decided to explore the reef. We actually had a nice dive, but didn’t see one shark; I later learnt the crew had never visited this reef before so not the smartest choice for a shark feed site.

Returning to the boat we were just about to ascend when I noticed a grey shape heading up the reef, it was a shark - finally one had turned up. As I watched the shape got bigger and bigger and bigger, this was no reef shark as I first suspected, but a creature with an odd-shaped head and very large dorsal fin. I then realised it was a great hammerhead, and it was huge, 4m long!

I had only been diving for three years at this time and had only seen wobbegongs, reef sharks and grey nurse sharks, but this thing was twice the size of any shark I had previously seen - and it was heading straight for me!

At this point I was starting to get a little worried as I had read that great hammerheads were potential dangerous and had attacked spearfishermen in the past. Flattening myself against the coral, I couldn’t take my eyes off the shark as I was mesmerising watching that T-shaped head sway back and forth, kind of like a snake charmer waving a flute.


Suddenly it was right in front of me and all I could focus on was its jagged teeth set in a jaw with a crooked smile. Those splayed teeth seemed to be heading straight for my head, but I had nowhere to go, so shrank down even further into the coral. Fortunately the shark wasn’t interested in making a meal out of me and lifted its head at the last second to skim straight over me and continue up the reef.

Ian, also squashed into the coral, and I looked at each other with wide eyes, amazed by the encounter but also a little scared. I then noticed two things, the shark was turning around and that I was lying on top of the baits – the baits the shark obviously wanted. Within seconds the shark came in for another quick pass, getting even closer this time. It was time to depart, before the shark returned.

Reaching the shot line we looked below to see the hammerhead homing in on the baits, it didn’t muck around, quickly grabbing one and swallowing it, then spinning around to pick up the second bait. With the food gone the shark lost interest and disappearing into the blue. The entire encounter only last a few brief minutes.

It was only when the shark departed did I realise I had my camera in my hand and hadn’t taken a single picture, too overwhelmed by the encounter. Later I was annoyed with myself for missing such a great photo opportunity, but I figured I would probably see another great hammerhead in the next year or so. Little did I know it would take me almost thirty years to see another great hammerhead!

The great hammerhead (Sphyrna mokarran) is found in tropical and subtropical waters around the globe and can reach an impressive 6m in length. These large sharks feed on fish, squid, crustaceans, small sharks and have an especially large appetite for rays, using their heads to pin the ray to the bottom as they feed. Their hunger for stingrays means they often get jabbed by the ray’s barb, with one shark reported to have fifty stingray barbs embedded in its jaw!


Hammerheads are thought to be one of the most recently evolved sharks, with their ancestors appearing around 20 million years ago. Why they evolved that wing-shaped head, known as a cephalofoil, is still debated, but the benefits it gives hammerheads is a greater surface area of electro receptors for detecting prey, it spreads their eyes for a greater range of vision and also provides lift for more efficient swimming. Generally a solitary animal, not a lot is known about great hammerheads, as until recently encounters have been rare and fleeting.

After that unforgettable close encounter with the great hammerhead I was keen to see another one and this time get a photo. Over the next two decades I booked on a dozen trips to the Great Barrier Reef and Coral Sea that included a shark feed, and while they were great dives not once did a great hammerhead show up. Speaking to the dive crews conducting the feeds they informed me that the odd great hammerhead does turn up, but they never hang around for long and encounters were extremely rare. I also read every dive magazine and shark book I could get my hands on and it seemed that hardly anyone had encountered a great hammerhead, so my experience from 1986 was starting to sound like a very rare and special encounter.

Over the years that I was hoping to encounter another great hammerhead my chances were declining dramatically with the species being decimated by longline fishers after their fins. Though listed as globally endangered on the International Union for Conservation of Nature (IUCN) red list, and locally protected in some areas, it is thought that their numbers have declined by 80% or more, the sad fate of many of our shark species, all for some tasteless bloody soup!

I was beginning to think I would never see another great hammerhead, but in 2013 hope returned when I read they were being seen quite regularly at shark feeds at Bimini in the Bahamas, but only over the winter months. Now convincing my wife Helen, another keen shark diver, to go to the Bahamas was not a hard sell, but with us based in Australia it was going to be an expensive trip. Luckily my fiftieth birthday was coming up, so a trip to the Bahamas sounded like the perfect present. Fortunately Helen agreed, especially as she was coming along.

A little research showed that there was a shore-based dive operator running trips to see the hammerheads, but if we were going all that way we wanted to do a liveaboard and also visit Tiger Beach, the famed tiger shark dive site. The vessel Dolphin Dream fit the bill and they had a trip doing both sites in January, only a week after my birthday, organised by Eli Martinez, from Shark Diver Magazine. We booked on and then counted down the months until we departed.


January, 2015, finally arrived and found us at Riviera Beach, 100km north of Miami, and on Dolphin Dream ready to depart for the Bahamas. The plan was three days at Tiger Beach and three days at Bimini, but wild weather wiped out the first two days and instead of diving Tiger Beach we ended up on the southern side of Grand Bahama reef diving. Fortunately on day four the weather improved and we could head to Bimini.

Arriving off South Bimini in the morning the crew quickly dropped a cage of baits in the water and started a chum slick. Within minutes we had several dark shapes below the boat – bull sharks. This was the last thing that we wanted as Eli explained that the bull sharks keep the hammerheads away - and they had been increasing in number on each visit.

After breakfast it was time to dive. Eli descended with a box of baits and the rest of us quickly followed. The visibility was terrible, barely 3m, not the best with half a dozen hungry bull sharks cruising around looking for food. Eli setup on the sandy bottom at 10m and started to scrap a fish frame with his knife. This got two nurse sharks very interested, they mobbed Eli, forcing him to constantly push them away. The bull sharks were also getting excited, sneaking around behind us, but they were too shy to take the baits.

After ten minutes a larger shape appeared on the edge of the visibility and from the very tall dorsal fin I knew it was a great hammerhead, finally after a 29 year wait.

This 4m long beast didn’t muck around, it swam straight up to Eli and took the bait on offer, then cruised right by me, its eyeball only inches from my face. It felt like a welcome from an old friend.

Almost immediately three other great hammerheads appeared from the gloom, almost like they were travelling in a pack, they are thought to be solitary creatures so this surprised me greatly. The sharks were all female and all around the same size, 4m long. For the next hour we watched these incredible creatures being hand fed, it was an amazing dive, but the best was yet to come.

For the rest of that day we had another two wonderful dives with the great hammerheads and fortunately the visibility improved, but by the last dive of the day the hammerheads had departed as more bull sharks had moved in. With the bull sharks causing problems it was decided to lift the baits and anchor nearby, giving the bull sharks a chance to disburse before we returned in the morning.


The following morning we finally got some beautiful Bahamas weather – flat seas, no wind, sunny skies and crystal clear water. The water was so clear that I could see the sharks below and it looked like we had five great hammerheads and only a few bull sharks. The four dives we did that day were just incredible; 30m visibility and up to six great hammerheads - a shark divers dream.

I shot over a thousand images, but having so much time with the sharks I found myself just watching these majestic creatures. I was really impressed by how graceful and manoeuvrable they are, that odd shaped head allowing them to spin on the spot, much more flexible and agile than any other shark species I had encountered. They were not aggressive at all, surprising considering the baits in the water and the reputation that they use to have, and I felt safer with them than I have with some reef sharks.

They also appeared to be very curious of the divers, as I found many times when I moved away from the feeding point to find clear water for photographs. Numerous times I had a hammerhead swim towards me that would tilt its head to one side so it could see me clearly from one eye. At the last minute it would turn away or swim directly overhead, then return for another look.


I was particularly interested to see if any had stingray barbs embedded in their jaws, but didn’t see evidence of any barbs. Eli showed me a stingray barb that he pulled out of one of the sharks the previous week, but added this is the first time he had ever seen one.

Eli has been diving with these great hammerheads so many times over the last few years that he can easily identify individual sharks and has nicknames for all of them. After several dives I was also finding it was easy to identify individual hammerheads. There was one male, he was the smallest shark, only 3.5m, and didn’t seem to be getting much food, Eli calls him Spartacus. Of the females one had a tag in its side, another had a dark pattern on the underside of its head and my favourite was one that had a blotchy pattern on its belly, these ladies are called Patches, Star and Cookie Monster. But the biggest female of all, around 4.5m, appeared to be pregnant and was quite shy, she just seemed to enjoy patrolling the edge of the pack and keeping an eye on things, she is called Bertha, but probably should be called Big Bertha.

After two incredible days with the great hammerheads it was hard to leave Bimini, but we had one last day to see our tiger sharks so lifted the anchor and headed north, but that is another story in itself.

I hope it doesn’t take another 29 years to see my next great hammerhead, but I am well aware that I may never see another one of these majestic sharks if more is not done to ban the hideous practise of shark finning. However, I live in hope that more countries will follow the lead of progressive governments like the Bahamas, which protected all sharks in its waters in 2011.