I STEPPED INTO THE CAGE, the crew secured the door and I was lowered into the water. I could hear over the comms system that Brian was already in his cage, secured to the back of the boat.
Just before we got in, Brian had said that he was a bit anxious, his last dive having been with me in Brighton Marina. We were now getting ready to come eye to eye with one of the ocean’s greatest and most feared predators.
I readied the camera and peered out into the blue, my finger poised over the “Go” button. A great chunk of tuna hung in the water between the two cages, ready to lure in this giant of the deep.
I tried to hold steady in my cage, but the ocean swell was giving us a buffeting.
I could hear Brian talking to camera about where we were and what we were looking for, when out of the corner of my eye I saw it. The shark was approaching from the left, passing within metres of Brian’s cage.
“Now that’s one big animal!” he shouted. “Look at those teeth!” I could hear Brian exclaiming at the sheer size of the beast (along with a whole load of “whooping”, which is quite unusual to hear from Prof Cox), when the shark made a sharp turn and went for the bait.
With astonishing speed and power the shark launched itself, mouth open, tail a thrashing blur. “I just got a faceful of shark!” All cameras were rolling.
We had had our first encounter with a great white shark.

WE WERE IN AUSTRALIA for a new BBC series, Wonders of Life, presented by Prof Brian Cox. In the previous two series Brian had tackled the Solar System and then the Universe, but for this series we were looking at something far more complex, the physics of the living world – something that by his own admission is a little outside Brian’s comfort zone.
My episode explores the size of life, and we wanted the Prof to experience one of nature’s largest predators, which was why we had come to see the great white sharks.
A couple of years ago, I had been responsible for prompting Brian to learn how to scuba dive. It was for a sequence for Wonders Of The Solar System, about Jupiter being a liquid-gas planet, but sadly the scene never made the final cut.
Now, as a newly qualified PADI Open Water diver, we had convinced him to try cage-diving. Our trip had started out from the small town of Port Lincoln, west of Adelaide in South Australia.
We were on a liveaboard dive-boat run by Rodney Fox, one of the oldest and most experienced shark-cage dive operators in Australia. Our destination was the Neptune Islands, a four-hour trip out from port, but the journey was pretty hideous, with rough seas and big swell.
Fortunately we all managed to sleep in our cabins through the worst of it. Now, moored up in the lee of the islands, the sea was a lot calmer and the sun was out, but the churning swell still made standing in the cages quite uncomfortable. We were, however, getting a lot of sharks.
For filming purposes, we had Brian kitted out with a special full-face mask made by Diveways from Japan.
Unlike other full-face masks, the Diveways models don’t have an oro-nasal section, so we get to see Brian’s lips move when he speaks to camera.
To clear your nose, there are “bobbles” that you extend inside the mask, and a valve to flush the air and reduce CO2 build-up. The mask is a little heavy, with its thick glass visor, but there’s not much more to it.
As the cages were held so near the surface, we were all fed by a surface supply. This was good, because there wasn’t much room in the cages and, with a tank on your back, we might otherwise have ended up whacking each other with the rise and fall of the swell.

THE GREAT WHITES circling the boat were awesome creatures. I had dived with reef sharks before, but nothing had quite prepared me for the sheer size and power of these giant predators.
Brian agreed: “These are wonderful, graceful beasts, brilliant at what they do, which is eat things.”
More than 4m long and pushing well over a tonne, these were true monsters.
Just before we got in, the skipper had mentioned to us that they had a metre-wide mouth, and could swallow a man whole. Not the most reassuring thing to say to a novice diver like Brian, but he took it in his stride.
As the sharks passed by within touching distance of the cage (we had been warned to keep our hands inside it), Brian noted: “They look like they’re eyeing us up, tilting their heads from side to side to get a better look with their large black eyes”.
He said he thought they were checking us out, trying to work out if there was any way to get at these strange creatures inside the cages.
For most of the dive, our cartilaginous observers would circle round, easing closer and closer to the bait. But occasionally, out of the corner of our eyes, we would catch a glint of silver, and a blur of activity as a shark erupted out of nowhere from the depths, shooting straight up to hit the bait from below.
“That was straight out of Jaws!” Brian looked over at me. “My cage got a good kicking! I felt the need to remove my hands.”
On board the boat, my topside cameraman was also getting some cracking shots of the sharks breaking the surface and flashing those rows of razor teeth.

OVER THE COURSE of the new BBC series, Brian has been getting wet at various far-flung places around the world. In an episode set in Mexico, he looks at what it takes to make our planet a home fit for life, with one of the vital ingredients being water.
In the Yucatan peninsula, he explores the famous limestone caves known as cenotes. These are huge subterranean cave systems that have been flooded by rainwater seepage. Interestingly, a whole set of these cenotes exist which, when seen from space, trace the outline of part of a huge circle. It’s thought that this might be evidence of a huge meteorite impact, possibly striking around 65 million years ago and playing a part in the demise of the dinosaurs.
Although the caves can be very dark and claustrophobic, the visibility is astonishing. “It’s so strange, because you can’t actually see the water,” observed Brian.
There isn’t a whole bag of life underground, but as the Prof was filmed snorkelling through one of the caves, he was joined by a freshwater turtle and some blind cavefish.
For one of the sequences, the director wanted sunlight to come streaming through the cave entrance, but none of the locals knew at which time of day this happened.
The team filmed all day without luck, and it was only as they were starting to wrap things up that the sunlight came streaming in. The rays lit up the cave like some sort of fairy cavern.
On the other side of the world, Brian went to Palau to witness another unique marine wonder of nature.
Taking a boat trip down to the southern lagoon to Eil Malk island, he had gone to see the golden jellyfish.
Once off the boat, it’s a steep and treacherous scramble up and over the limestone rocks to an inland marine lake, the home of these amazing animals.
As young polyps, the jellyfish engulf (but don’t eat) a certain species of algal cells, which they then keep alive within their tissues. The jellyfish have evolved a complex symbiotic relationship with the algae – they provide these Scyphozoans with food through photosynthesis.
Each day, the jellyfish migrate along the length of the lake, tracking the sunlight and resetting themselves overnight for the next day’s sunrise back at the far end of the lake.
From the surface, Brian said he could see just a few jellyfish wafting around, nothing too special. “It was only when I went in snorkelling – no scuba allowed – that I realised the sheer numbers of the swarm that inhabit the lake, with several million of these golden jellyfish.”

BACK ON BOARD the liveaboard boat in Australia, our second day with the great white sharks was proving as fruitful as the first. We had been well looked after on the boat with great food and comfortable bunks and, following a glorious sunrise over the islands, had managed to capture some great footage.
I even managed to film Brian in the cage explaining the science of streamlining with an inquisitive shark peering right over his shoulder. “That distinctive shape is a response to the laws of physics,” he said.
Along with the great whites, by taking a cage down to the seafloor we also filmed mako sharks and bronze whalers, as well as some rays the width of a car. The Prof was very taken by the great whites’ elegance and grace, commenting that he didn’t see these behemoths as any sort of brainless, prehistoric killers, but as curious, intelligent and incredibly well adapted as one of the ocean’s most fearsome predators.
“I just went face to face with a great white, and it was unbelievable,” he said.

Wonders of Life is due to be screened on BBC2 this autumn.