The idea of SCUBA diving with a Nile crocodile didn’t seem like a good one, even with the added value of retrospect. Particularly since the animal in question was wild, and not the only toothy predator lurking around our boat. Jumping overboard in Botswana’s Okavango Delta with full wet suit, tank, fins and mask was just the beginning of this adventure, and my own well-honed sense of self-preservation was on high alert.

When doing anything this risky one has to have a very good reason, this was not blind recklessness but rather a genuine fascination for a hidden environment and its inhabitants. Our mission here was to finish a film - South African production company Earth-Touch had delivered “Diving With Crocodiles” a year before to the prestigious Smithsonian Network. We’d moved onto our second offering, which is destined for National Geographic, so we had to up the pace and come up with something new. I’d dived in the delta’s channels 15 years ago, but that wasn’t to actively seek out the crocs, it revolved more around seeing what was beneath - but avoiding the reptiles at all costs. This time we wanted to film big crocodiles in the Okavango river and its side channels, we had dived with and interacted with numerous crocs underwater the previous season, some over 4 meters in length. Now to take things even further, we also wanted to follow them into the black abyss that runs underneath the vast papyrus beds.

On this current mission crocodile researcher Vince Shacks, safety diver extraordinaire Richard Boltar and I had to get more shots of big crocodiles underwater, and map out the dark cave systems that they use to get around the delta system.

For those who don’t know the “panhandle”, it’s where the Okavango river channels down a narrow sluice before fanning out into the actual delta. Picture the gnarled handle of a shredded and rusted frying pan. At certain times of the year, the water runs clear here and one peek beneath the surface reveals an amazing parallel world that exists alongside the wonder of the delta’s surface wildlife. From beneath, water lilies aren’t green, they’re a rich purple, and they flower underwater too. Little minnows have blue eye-shadow or tiger stripes and parts of the Okavango lagoons look like manicured stands from the Chelsea Flower Show.

In the main channel of the panhandle the flow is much stronger. The first thing that strikes you here is the color. You’re in an electric emerald green world. The water is cold, and this seems to add to the clarity. Looking up at the papyrus banks as you drift past a few meters below is enchanting. The riverbed is equally interesting. There don’t seem to be many rocks in this part of the Botswana so the water sculpts the hard mud of the riverbed into weird shapes - ridges and drop-offs, shallow riffles and deep rounded bowls. Vast shoals of Tigerfish and bream loom in the sunlight and old wrecked mekoro canoes can be seen lying desperately on the bottom. Each one has probably got a story, and chances are they involve the resident crocodiles!

People often ask how we’re able to dive with such a terrifying creature. In short, I feel that we stumbled through one of nature’s loopholes. Nile crocodiles are apex predators and they vie with the hippo for pole position as the most dangerous animal on the continent. To use the cliche, diving with a croc isn’t something to try at home, but slowly and surely we’d found it very possible and quite exhilarating. Finding the crocs is quite easy; wait for them to get warm, and motor along the channels in a boat. You can see them lying on the bank, thermoregulating, sometimes with their mouth ajar. They all dive beneath the surface, and this is where the guess work begins. You have to jump overboard and find them, after checking for hippos first. Once we’ve located an animal we can normally swim quietly up to it and lie with a foot or two. We don’t try to get too close to the really big animals of four meters plus, but prefer the three meter range. To say that there’s a connection between human and crocodile here is plain naiveté, we are not under any illusion of grandeur. This is a very successful predator with a strong sense of self preservation, which is why it’s existed for so long unchanged. Once the croc wants to go there is no way we can keep up and track it. They have many escape routes in the delta, they don’t need much room beneath floating foliage and they’re experts at hiding.

Which brings us to the papyrus. This plant is the “skin” of the Okavango panhandle. The river winds through it, but that’s just a peek at what really goes on. The papyrus floats and beneath it lies an entire aquatic system, the extent of which most of us cannot comprehend. Think of the river as the strongest part of the current; everywhere else water flows in smaller fingers and tendrils, moving in and out of the main channel and hidden lagoons. These spaces are collectively vast, but dark and foreboding - a perfect crocodile fortress. We’d worked this all out one day when we were filming Earth-Touch’s first croc film. One day a 3 meter croc that we were swimming with disappeared into a shadow beneath the bank. When we swam under it, we discovered that there was no solid bank but rather a roof that extended out into the channel. We could have swum 50 or 60 meters into this black muddy space, but we didn’t have a torch so the crocodile vanished.

On this trip we wanted to explore the caves, Vince wanted to see for himself what goes on under the papyrus, and why the crocodiles use this concealed network. This sounds like an irresponsible whim, but how many things can you do these days that no one else has ever done? Making original films these days usually involves risk, and we all had enough of a sense of adventure to be the first to grope around deep beneath the papyrus beds. It was Vince’s crocodile research project that had fueled our enthusiasm for diving with the reptiles. We began photographing the tail scutes of individuals to see if Vince had tagged them before. This way we could add to his database of animals and work out where these bigger animals were last seen. Vince had something else up his sleeve, he wanted to test the eyesight of a crocodile underwater.

For the most part its known that crocodiles can see well, but when they submerge their vision is affected by the nictitating membrane that slides over the eyeball. Certainly in our own experience we’d swum with crocodiles that had collided with objects on the bottom of the river. We put this down to a lack of clear vision, and what Vince wanted to do was appealing to our film too. His experiment involved flash-photographing the eyeball of the crocodile from close range. The red reflection from the retina gives accurate information on how focussed the eye is, whether it’s short or long sighted.

But the first mission was to explore a cave systems, and on our recent trip we had found a wonderful cave system off the main channel. The Okavango flood was still running high, so the papyrus was well floated, hanging meters above the river bed in places. Our pan was to enter the cave with torches, and attempt to penetrate a hidden lagoon or island on the other side of the papyrus. Dropping overboard is quite daunting because this has to be done quietly and quickly. We acknowledged that our saving grace with the crocs is the noisy SCUBA bubbles and the fact that we always meet them on the bottom. Flapping around on the surface triggers the opposite response - they seem very interested in eating you. Once we’d hit the bottom and got our bearings we swam towards the darkness where the bank should be. Swimming in is terrifying because when you’re in the light you can’t see into the dark, no matter how powerful the torch is. You have to poke your head into the shade before you see where to go and whether anything is waiting in there. In our case it was all clear, and a huge space opened up in front of us.

Looking ahead, it was like diving in ink. It was only if we turned that the emerald glow of the channel appeared. The floor was hard white sand, so there was little sediment but the ceiling near the entrance was about 2 meters above the floor. The torch beams illuminated the underbelly of the papyrus beds above us, dark root stems with tiny white hairs waving in the current. Swimming further into the blackness, huge root clods appeared, fallen from the mass above. Every now and then an green shaft of light speared down from a peep hole above. Good breathing holes for crocodiles…

We needed a few minutes to settle in here, I am bordering claustrophobic so I had to keep a handle on things. Looking through the camera helped. Once we’d relaxed a bit other things became obvious. Every now and then huge catfish were lying on the floor, preferring the mud to the sand. Looking closely at these mulch sections, the cave bottom is covered in little Tiger barbs. On the root ceiling Squeaker fish live a life inverted, swimming upside down. We swam further in, probably 60 or 70 yards when we began to see a glow ahead. A much smaller tunnel led into an open pool, just a few meters across. We could surface briefly into a gap in the papyrus, but on all sides it was still dense. We retraced, through the green tunnel and into the main hall of the cave beyond. We could follow our own sediment clouds in the torch beams, and eventually we saw the distant kryptonite glow of the entrance. It’s an amazing glance at a crocodile transport system, with good cover, food available in the form of catfish, and breathing holes en route to hidden parts of the delta. We felt privileged to have been the first to see it.

The next job was to find a crocodile for Vince’s eye test. For this we hunted the open channels looking for an animal of around three meters. We found one on the edge of a deep pool, and it dived in. We followed and found it lying among the mud clods at the deepest part of the pool. At thirteen meters we had to watch our air, but we settled next to the animal and it seemed to tolerate us. Vince and Boltar edged closer, well aware that they were dealing with the business end of the animal. Unfortunately for them, the eye is near the teeth! Vince snapped off a few pics, edging closer all the time. This went on for about 20 minutes, and eventually the crocodile moved off along the bottom with that wonderful “grabbing” gait, gripping onto the mud with huge clawed feet.

The result of the test was as we’d expected, Vince wants to publish this info, so I can’t tread on the facts, but this particular croc didn’t seem to be focussed on us at all. In fact we got similar results to those a human eye would give underwater, without the luxury of a diving mask. Just blurred color.

Being part of something like this is special, I’ve been lucky enough to be introduced to a place where humans have never been. It’s like the deepest part of the ocean; we’re aware of it but we don’t know what goes on there. The Okavango underwater really adds to the aura of Botswana as a country, which has so much to offer in terms of natural heritage and their attitude towards it. I’m not quite sure what will happen now that a small part of this system has been “unlocked”, but its certainly worth seeing, but only carefully.

We have no idea of how consistently the crocodiles will accept us. Since this trip Boltar was approached aggressively by a 4 meter croc. He’s a careful guy, and he managed to fend it off with the stick that he dives with, but who knows what really went on there. We have to be very very careful.

On the other hand, we have to give the crocodiles some credit, they are discerning predators that just can’t be mindless. They’re very careful, but no less dangerous and we have to remember this.

About the Author: Graeme Duane is Creative Director of Earth-Touch, a film production company based in Durban, South Africa.

He has 21 film credits for National Geographic as director of photography and has spent that last 10 years filming on the African continent for a variety of productions.

More recently Graeme has been producing Earth-Touch’s crocodile films, where he and the crew began diving with the reptiles 4 years ago. Since this time many things have been learnt and Graeme’s production team has filmed unique scenes involving crocodiles of over 13 feet in length.

© Earth-Touch 2011