Big Fish Story: Snorkelling with Whale Sharks on the Ningaloo

William Gray slips into plankton-rich seas around the Ningaloo Reef of Western Australia, hoping for a glimpse of the world's largest fish

This article was originally published in The Sunday Telegraph

“Jump in – go for it!” These were words I never expected to hear in the vicinity of a large shark. Odder still was that I found myself wearing a wetsuit, mask and snorkel. I’d been told whale sharks were harmless, but so are buses until they run you over. It wasn’t so much their 3,000 tiny teeth, nor the fact that they can weigh 40 tonnes and spend their lives hoovering plankton like enormous floating Dysons. It was their eyesight that bothered me. No one seemed to know whether the whale sharks would be able to see us in the soupy waters off Western Australia’s 260km-long Ningaloo Reef. Our guide had warned us to keep at least 3m away. But had anyone told the shark with the metre-wide mouth?

“It’s coming straight for us,” said our skipper. “You can’t miss it.” The time for deliberation was over. Suddenly I was caught up in a rush for the boat’s stern as the others began flopping overboard like exuberant sealions.

Diced into flickering shards, sunlight probed the plankton-rich sea, transforming jellyfish into glowing orbs and igniting the fizzing turmoil of the swell. I felt powerless – my strength sapped by the rollercoaster sea.

Visibility underwater was poor – like trying to peer through a blizzard. Diced into flickering shards, sunlight probed the plankton-rich sea, transforming jellyfish into glowing orbs and igniting the fizzing turmoil of the swell. I felt powerless – my strength sapped by the rollercoaster sea. There was little I could do but tread water and try to act ‘unplankton-like’. The 10m shark appeared right in front of me, its letterbox mouth agape, ploughing through the turbulent water like a trident submarine. Its skin was a beautiful mélange of stripes and spots, caressed by a lacework of sunlight. The effect was ethereal. Despite its bulk, the shark blended seamlessly with its surroundings – as unobtrusive, it seemed, as the translucent jellyfish. Entranced, I almost forgot the 3m-exclusion zone and began frantically back-pedalling. But it was obvious that the shark was aware of me. With no discernible movement of its great tail or splayed pectoral fins, it banked into a graceful turn, an entourage of tiny yellow fish following in its wake. The encounter had lasted barely 30 seconds.

Of the handful of whale shark hotspots (such as Honduras, Mexico, South Africa and the Galapagos Islands), Australia’s Ningaloo Marine Park is one of the best placed. Not only do the sharks congregate here in good numbers between March and June, but they are easily accessible – usually cruising just beyond the reef which is only 100m offshore at its nearest point.

My base was Coral Bay, a one-street cluster of caravan parks, a hotel and backpackers, plus a few shops and restaurants at the southern gateway to the marine park. It had a bare-foot, frontier feel; an offshoot of the Perth-Exmouth road simply fizzling out on its beach.

Whale sharks are not the only marine heavyweights to lure snorkellers to Coral Bay. Measuring up to 7m across and weighing two tonnes, manta rays congregate in the shallower, calmer lagoons. Gliding like gigantic aquatic bats over the sandy seabed, they are easy to spot.

It’s a different story, however, in the open ocean beyond the reef. An hour had passed since our first whale shark encounter and euphoria had subsided into nausea. All eyes turned skyward, tracing the tiny white speck of the spotter plane circling overhead. “From up there, even a 10m shark looks like a tadpole,” the pilot had told me the previous day.

Although whale sharks are the world’s largest fish, aerial reconnaissance is still the best way to spot them. There is never any guarantee you’ll see, let alone swim with one. Whale sharks are shrouded in mystery. No one knows how many there are, where they breed or what triggers their trans-oceanic migrations. These enigmatic creatures can dive to depths of 700m, yet feed on blooms of plankton at the surface. They can reach 18m in length, but how long they live is unknown.

The IUCN lists the whale shark as ‘vulnerable to extinction’. Apart from orcas, humans are their greatest threat – a single Indian fishery is believed to have killed over 1,000 between 1999 and 2000. Shark fin soup commands a high price – but ecotourism could provide an economically viable alternative to hunting, as long as it is properly managed to minimise disturbance. “This is a ‘hands-off’ experience,” our guide had warned us at our predeparture briefing in Coral Bay. “If you get too close, I’ll tug your fin – three tugs is a red card offence and you’ll be back on the boat.”

I had no misgivings about slipping into the water alongside a whale shark for the second time that day. The boat’s radio had abruptly crackled into life with a new aerial sighting, and minutes later we were back in the water. Steadily, methodically, the shark pulled ahead. Despite the first twinges of cramp in my legs, I tried to keep up – but it was hopeless. It began to dive and I found myself craving an aqualung so that I could follow it down. Scuba gear, however, is forbidden. “When they dive,” our skipper had told me, “you’ll just want to dive with them. Before you know it, you’ll be at 40m and still descending – it’s too tempting; too dangerous.”

I could see what he meant. As the shark sank beneath us, I watched the spots on its back turn luminous blue – pulsing like fireflies. Snatching a breath of air, I folded at the waist and dived after the strange lights – a final impulsive action. But after a few seconds, my sinuses protested and I spun upright, groping for the surface.

As the others clambered aboard the launch, I lingered off the stern, sneaking glances underwater. But it was wishful thinking. The whale shark had gone and the only lights in the sea were the flecks of plankton shimmering in columns of early evening sunshine.