“We’re brought up bombarded by the concept that crocodiles are very vicious,” says wildlife photographer Amos Nachoum. “If you come close, they will immediately kill you.” It’s a fair reputation: two and a half million years of evolution have made the Nile crocodile one of nature’s most specialised predators, capable of taking down almost any prey – including a shark. You wouldn’t want to find yourself in the water with one. Unless, of course, you’d signed up for one of Nachoum’s diving tours.
The itinerary, at a glance, resembles a regular dive excursion – six nights at a fully catered safari lodge, five days of dives in Botswana’s Okavango Delta, with all equipment supplied. But on this trip, there’s a medic. Plus photos of you on the riverbed, nose-to-snout with prehistory’s deadly masterpiece in its natural habitat – yes, without a cage.
“Underwater, the croc is different,” explains Nachoum. “It’s peaceful. It almost seems harmless.” The same specialisation that makes the crocodile a master hunter has built in behavioural backdoors to its predatory instincts, which skilled divers have hacked into. In the sediment-rich waters of the Nile, the croc’s eyesight is relatively poor. Lurking on the riverbed, it scans the surface for silhouettes against the bright water – a wildebeest, zebra or careless diver. The trick is get out of the kill zone quickly – a tactic developed by photographer Graeme Duane when filming a documentary for National Geographic.
“We found that if you jumped off the boat and screwed around splashing, they came to see if it was something they could eat,” says Duane. “Whereas if you sank straight to the bottom and engaged with them there, it’s a very different ball game. They’re not sure what you are, and whether to be scared or aggressive.”
Diving during winter opens up further opportunities. In the cooler months, male crocs’ testosterone levels drop, making them less territorial. With the water temperature around 16°C, their slowed metabolism makes them less inclined to feed and more concerned with conserving their energy. Simply put, they have to work out whether biting you is worth the effort.
“When you lie next to the croc,” says Duane, “you can see it’s calculating, processing information. It wants to check you out – it actually engages with you. They’re not afraid of much, but they have a strong sense of self-preservation.”
Crocodiles are terrestrial animals rather than true amphibians, which means they can’t eat under the surface without swallowing large amounts of water and drowning, but that doesn’t mean they’re defenceless. Which is why Nachoum is picky about who he takes along. The expedition is only open to divers with at least 100 hours of dive experience, and excellent buoyancy control is essential. Fast-moving currents and a claustrophobic environment mean a wrong move could send you into a croc’s bite radius. Their jaws are studded with pits that act as pressure sensors. “You don’t want to wake up those sensors,” says Nachoum. “They can’t open their mouths straight upwards because of their thick neck, but if anything comes alongside, they’ll snap left or right.”
Duane has first-hand experience of the risks. During one dive, he found himself trapped in an underwater cave with an aggressive croc. The 3m-long apex predator kicked up sediment with its tail, blinding him, then rammed straight into Duane’s solar plexus. ”Fortunately, it didn’t snap. It just winded me and took off in another direction,” he says. “Which was a stroke of luck.”
And if things go wrong? Poke at the crocodile. Duane’s colleague Richard Boltar used a spear to fend off an attack. “As long as you’ve got something between you and the croc, you’ve got a pretty good chance,” He says.
animal instinct: More chances to get close to nature