ITS GIANT MOUTH APPEARED FIRST, heading directly for me, not more than 10m away. As it grew closer, I saw the inimitable pattern of spots and stripes. This was the largest fish in the sea - a whale shark. Exmouth Diving Centre 00618 9949 1201, www.exmouthdiving.com.au
It was more than 7m long and had several hitchhikers - three remora clung to its belly and a halo of baitfish surrounded its head. I hung motionless, awestruck, as its powerful tail propelled it past me.
Immediately the stampede of other snorkellers overtook me. As their fins thrashed through the water in fast pursuit, I saw the whale shark descend rapidly to the depths.
One of the other snorkellers had gone too close and kicked the shark in the head - no wonder it had dived.
I was one of 20 divers on a whale shark adventure tour led by Exmouth Dive Centre. Like the others, I had made the long journey to the small town of Exmouth on the North-west Cape, a sliver of West Australian outback protruding into the Indian Ocean, for the chance to see these great animals in the wild.
Every year large numbers of whale sharks - some estimate up to 300 - appear in the waters off Ningaloo Reef shortly after the coral spawnings of March and April. There they stay until late May or early June, travelling close to the surface and allowing groups of snorkellers to swim with them. For many, its the experience of a lifetime.
SINCE THE LATE 1980S, when it was discovered that the arrival of the sharks is an annual event, a small eco-tourism industry has developed. The use of spotter planes has made the business a very efficient one. Indeed, your chances of seeing a whale shark are greater at Ningaloo Reef than at any other place on Earth.
Back aboard the dive boat, the careless snorkeller received a stern warning from skipper Andy Edwards that if he got that close again, he wouldnt be going back in the water.
WITH A DIRTY-RED GOATEE, sunglasses and a floppy, wide-brimmed hat, Edwards has a tough look about him. Like many working in this industry, he has a background in fishing. For the past eight years he has skippered boats for whale shark tours.
Its his job to communicate with the spotter pilots and get people what theyve come for - whale sharks.
Once a shark is spotted, the boat is positioned well in front and the divemaster gets in the water. He swims alongside and allows the skipper and the group to mark the position and direction of travel. The divers enter the water, the shark passes, and they snorkel beside it.
Because of the speed at which a whale shark moves - which can be several knots - snorkelling has proved more effective than scuba.
ALL WAS QUIET ON THE DIVE BOAT as we waited for the whale shark to resurface. We knew it might not do so. After 10 long minutes, the marine radio began to crackle - our shark was back up.
As Edwards pulled the boat around hard, I nearly lost my balance. A moment later we were back in the water. This time we were cautious. As the shark approached, we kept our distance, giving it more space. It was travelling about a metre below the surface.
The distinctive spotted pattern on the whale sharks back appeared to change with the play of the sunlight coming through the waves. The effect was mesmerising. Looking down, I could see two claspers on its underside. This was a male shark.
It appeared to glance at me with its small black eye as I swam alongside, not seeming to mind my presence. The heavy ridge running down its back gave it a prehistoric look, but its wide, flat head resembled no shark I had ever seen. The massive tail moved from side to side in broad sweeping arcs, giving the illusion that it was not moving very fast, yet it was in fact travelling at considerable speed.
MY DUCK-DIVES TO PHOTOGRAPH THE SHARK grew shorter as I became fatigued. Other snorkellers fell behind, my thighs began to burn. After about 15 minutes, I was too exhausted to continue. I returned to the boat to reload film and rest.
Touching or riding whale sharks is strictly prohibited. However, in the early days riding was a common practice.
They always dived when we rode them, Edwards recalls. A sudden dive is an indication that a shark has had enough. Other signs are a visible shiver - their whole body shakes - and flickering of their nictitating membranes. Then they pick up speed and dive. They dont like divers close to their heads.
WHEN THINGS ARE GOING WELL, the sharks appear to be oblivious to divers. Often they wont even alter their course when people are in their way - its the divers that must move.
In the week I spent at Exmouth, there were between three and five sharks out most days. It was only after several hours of swimming with them, and much fatigue, that we went in.
In his years working at Ningaloo, Edwards hasnt noticed any major trends in numbers of sharks. They do vary from year to year, however. 1995 was a really bad year for sharks, he recalls. We were afraid wed scared them away.
Research indicates that changes in water temperature and currents might affect their movements.
ON DAYS WHEN FEW WHALE SHARKS ARE PRESENT, several boats might be forced to share the same shark. Were aware of how far people have come and how much theyve paid, says Edwards. Theres a philosophy between skippers that everyone on all the boats gets an equal opportunity with the sharks.
Known as getting out of jail, this is the fulfilling of the guarantee all operators have with their customers - if no sharks are seen, they come back for free.
That pressure on the operators, and the growth of the industry, has led to the need for government regulation.
The whale shark is a fully protected species in Australia. All operators require government licences to run interaction tours, and must adhere strictly to the industry code of conduct.
Under that code, divers must not approach closer than 3m from the head and 4m from the tail of the shark. Boats must not approach closer than 30m and a maximum of 10 people are allowed in the water at a time. Operators are also required to collect basic information such as size, sex and location of the shark.
Our approach was based on the whale-watching industry, says Doug Coughran, Senior Wildlife Officer for CALM, the West Australia Department of Conservation and Land Management, a government organisation that oversees the whale shark industry. We looked at the approach to managing people around whales and modified it for the different type of interaction.
By dropping people far forward of the shark, theyre able to swim to one side, out of the sharks way, lessening the disturbance. He adds that consultation with the industry is ongoing and changes are made to the code when necessary. Our goal is management for maximum contact with minimum impact.
Unfortunately, many countries fail to realise the true value of these animals and the lucrative tourism dollars they can bring.
With the decline of traditional fisheries, fishermen in India, Thailand, the Philippines and Indonesia have turned to hunting whale sharks as an alternative source of income.
THE HUNT IN INDIA HAS BEEN PARTICULARLY DEVASTATING. According to one report, in the western state of Gujarat, India, three villages alone slaughtered some 1000 whale sharks in 1999.
The fins are exported all over Asia to make shark-fin soup. In Taiwan, whale shark meat is much sought after - its taste is described as resembling tofu.
Facing pressure from conservation groups, this May India placed a total ban on whale shark hunting. However, the reprieve might be only temporary.
The Asian market for whale shark has been created and will be looking elsewhere for supplies, says Marie Levine of the Shark Research Institute. Until the whale shark has global protection via CITES, the species is very vulnerable.
She explains that no one knows how many sharks were killed in India or if any fishing industry is sustainable.
Nor is it known if the whale sharks that visit Ningaloo Reef are the same sharks that are being hunted. Where they go when they leave Exmouth remains a mystery, because they have proved very difficult to track.
CONVENTIONAL SATELLITE TRACKING DEVICES are effective only on animals that break the surface, such as marine mammals. And the tough, thick skin of the whale shark has caused problems attaching tags.
Some even fear that the presence of boats around the sharks might lead to habituation, making them more vulnerable in areas where theyre hunted.
But until their movements are known, its impossible to determine what effect the fishing is having on them.
We need good science, says Doug Coughran. All the protection here isnt going to do anything if they go somewhere else and are hunted.
THAT AFTERNOON, JUST AS WE WERE about to head in for the day, our spotter pilot radioed us the position of another shark. After several hours of swimming with the first whale shark, our group was very tired. Only three of us had enough stamina to go back in.
It was another male specimen, 5 or 6m in length. Just as we got alongside, it threw its mouth open, wide enough to swallow a diver.
Was this whale shark yawning or just posing for us
As there was no food in this blue water, it was clearly not feeding.
Feeling like Jonah with a camera, I got close and finished my roll of film. Despite the Hoover-like pose, it was still moving at very high speed.
A moment later, it closed its mouth and began to descend.
The lactic acid was building in my thighs. I waved to Edwards to be picked up, thankful that I made this final drop, and that the town of Exmouth had the foresight to manage these incredible animals in such a positive way.
WEST AUSTRALIAS WHALE SHARK ECO-TOURISM INDUSTRY might serve as a model for other areas where whale sharks visit.
Its a good example of industry and government working together, says Doug Coughran. Its a model thats working well.