Exploring the less popular west coast of Australia, which houses the stunning 260km Ningaloo Reef, Rough Guides writer Helen Ochyra has a close encounter with the ocean's biggest fish.

I am being pulled through the water by the hand, bubbles rushing past me on both sides, the only noise my own breathing. With every kick of my flippers I am more and more exhausted, those breaths coming faster and shallower, the tug on my arm more and more persistent. I am just about to give up, spit out my snorkel and put my head above water when – there it is. The ocean’s biggest fish swimming right alongside me. A whale shark, some seven metres long and almost within touching distance.

This is what we have all come to see – not just our group of 10 (the maximum number of swimmers allowed in the water with the whale shark at any one time), but pretty much every single person currently staying in Exmouth on Australia’s west coast. The months between April and July are whale shark season here and sightings of this vast creature are almost guaranteed in the waters of Ningaloo Marine Park just offshore.

Ningaloo Marine Park reef, Australia

There may be plenty of them out there, but our tour operator, Ocean Eco Adventures, is taking no chances, sending up their very own spotter plane to track down the whale sharks and make sure our boat heads to the right areas – and gets there ahead of the other operators.

Within Australian waters whale sharks are protected by the Wildlife Conservation Act. Just one boat at a time is allowed within the so-called “exclusive contact zone”, an area of 250 metres radius around the whale shark, and so if we arrive second we have missed our chance. Fortunately, the plane and our boat are in constant contact, the boat moving around Ningaloo according to the plane’s whale shark sightings, and so we can find whale sharks away from other boats.

We also have several snorkel guides to get us all into position – and they don’t waste any time. We are in and out of the water continuously, leaping in from the back of the boat as soon as a whale shark comes into view. We have just seconds to strap on our mask and snorkel, waddle in our flippers to the platform and dive in. “Faces in the water,” they yell out, and we’re off, those of us not quite keeping pace pulled along by the hand.

For me, keeping pace is proving tricky; the whale shark may appear to be moving sedately, but it cuts through the water with speed, propelled by a graceful but powerful flick of the tail. I swim frantically alongside, examining its checkerboard of large pale spots – a unique fingerprint that reaches all of the way along its back – and its shark-like fins as they move through the water.

Whale shark, Ningaloo reef, Australia

As I watch, mesmerised, it gradually begins to dawn on me that I am keeping pace at last. I am mimicking its swimming style, legs kicking more slowly but with more power, arms folded behind my back rather than flailing in front of me. I get into a rhythm and calm descends.

But then the whale shark alters course. Its tail swings through the water away from me and I realise that this can mean only one thing – it is turning towards me. Suddenly I find myself facing the largest mouth I have ever seen. Because the whale shark is a filter feeder it has a mouth more than a metre wide to capture as much water – and therefore as much plankton – as possible. If it opened its jaws I feel certain it could swallow me whole.

I also feel certain that I should get out of its way. This may be a gentle giant but it is still, well, a giant. And so, once again I am all flailing arms and kicking feet. Seven metres of whale shark heads straight for me – and straight past me. I am so close I could reach out and touch it but this is, of course, against the rules, so I simply watch, dumbstruck, as it swoops past me and on with its journey.

Nobody knows where they are heading, or why they migrate past here every year, but one thing is for sure – swimming with them is truly incredible.

Explore Australia with the Rough Guide to Australia. Ocean Eco Adventures offer day trips to swim with the whale sharks from $395. For more information visit westernaustralia.com.

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