Freediving with Bull or Zambezi Sharks – Carcharhinus leucas

Distribution and Viewing

The Bull, or ‘Zambezi” shark as it is known in South Africa, is considered by many shark experts to be the most dangerous to man in terms of attributed attacks and fatalities. Distributed world wide in all tropical and subtropical regions, its ability to tolerate extremely low salinities enables it to swim huge distances up fresh water systems, where it has been known to attack animals and humans. Wary by nature, Zambezi Sharks make for challenging photographic subjects and in my experience I have had greater success with these animals while freediving than on scuba.

In South Africa there are a few dive operators who specifically target Zambezi Sharks from a photo-viewing perspective, specifically Trevor Krull in Shelly Beach. In southern Mozambique, the local dive operators have had good results with Zambezi Sharks off the Pinnacles between November and April, click here to read an account of a photographic expedition done there recently.

Subject Behaviour

Potent predators, Zambezi Sharks will regularly approach divers underwater and steal fish from spearfisherman’s spears, a scenario which makes for compelling imagery. Most encounters are relatively relaxed however, with the Zambezi Shark generally approaching the diver slowly on or near the bottom before slowly swimming off out of sight. I have on two occasions been mock charged by Zambezi sharks while spearfishing, as have countless other spearfisherman, an experience which one does not easily forget. . In both instances the shark approached at a 45 degree angle from the bottom, moving at full speed, before breaking away at the very last minute.

A good percentage of recorded human shark attack fatalities have been attributed to this animal, and it is certainly advisable to keep your eyes peeled when diving with Zambezi’s. particularly when they are around in numbers. As with all sharks, they have a special talent for approaching unnoticed from behind the diver, so it makes sense if freediving to have one diver up acting as a spotter for such activity - by making a drumming sound with one’s tongue underwater it is possible to send a warning to the diver who is being approached. In my experience, screaming underwater does appear to intimidate Zambezi Sharks and cause them to back off, although I would only recommend using this technique in an extreme situation.

Photographic and Stalking Advice

Zambezi sharks are not that easy to get very close to, so its imperative to adopt a submissive posture in the water and allow the animal to approach you rather than swim after it. Zambezi’s also appear to prefer to be underneath or on the same level as you, so its quite tricky to get yourself into a position where you can shoot up at them. The best way I found of doing this was while freediving - swim very hard and fast down to around 25 meters, and then let the Zambezi’s swim in towards you from the higher plane.

Zambezi ‘s move very deliberately, neither slow nor fast, so I would recommend shooting on a shutter priority of no less than 1/180 s. Their bellies are extremely reflective, so its critical to get the right power setting when shooting up, especially when deep. Unlike Tigers, Zambezi Sharks tend to avoid coming too close to the surface, so its difficult to shoot them on ambient light unless in very shallow water. If you are shooting without strobes, shoot extremely wide angle and include divers in your shot to create an atmospheric feeling - I really enjoy this type of image, perhaps because it reminds me so much of freediving.

In terms of lenses for the Zambezi Shark, I would recommend working within the 18mm to 28mm range.

Interesting Observed Behaviour

On the Pinnacle of Ponta Mamoli, Barry and I saw a mature female Zambezi Shark suddenly veer towards the surface and try and eat the remora fish that has been attached to her just a few seconds earlier. The remora easily evaded her efforts, and then calmly resumed position alongside her, suggesting that this is a relatively common occurance.