I can feel the difference the minute I exit Exmouth airport – a stillness. The sky is a vast bowl of blue and, when I hit the road, nothing but heat-shimmered asphalt lies in either direction, flanked by red earth, scrubby vegetation and termite mounds. Previous arrivals into developed Cairns have come with a sense of pace.

Both Australian coastal cities – more than 3,000 miles apart – are gateways to world heritage-listed reef systems. The Great Barrier Reef, accessible from Cairns, is the world’s largest coral reef; Ningaloo, reached from Exmouth, is the world’s largest fringing reef – often so close to the shore that two kicks will have you above the corals.

It’s also reasonably accessible, as Western Australia’s capital Perth is the only Australian city with non-stop flights from the UK. I’d chosen a stopover route with Singapore Airlines, so I could hit the ground refreshed and ready to explore.

Although Perth’s hotels are as cosmopolitan as you’d expect from a state capital, remote Exmouth’s are generally rather basic.

However, fancy hotels aren’t the reason to come here. Ningaloo is remarkable for its whale sharks – the largest fish in the world – drawn by the plankton and krill at the annual coral spawning. These huge creatures are filter feeders, with astonishingly tiny teeth – although they do have around 3,000 of them.

The sand dunes of Ningaloo (Photo: Tourism Western Australia)

Last year, more than 40,000 tourists travelled to Ningaloo to swim with them, a number far less than the Great Barrier Reef’s 2.24m.

Strict protocols mean that the experience is tightly controlled. Just 14 operators are licensed to conduct whale shark tours in Ningaloo Marine Park, with a maximum of 10 swimmers in the water at a time. Although the reef is easily reached from shore, it’s a longer boat ride out to the whale sharks, giving the crew ample time to brief us.

Nothing can prepare for seeing a Whale Shark (Photo: Ningaloo Discovery Tours)

For many, a swim with these “gentle giants” of the sea is a bucket-list experience. Whale sharks generally swim alone but, if you do chance upon a group, it’s a “constellation”.

Nothing could prepare me for the first sighting. At the call: “heads under, NOW!” I’m suddenly confronted by a gaping mouth almost as wide as my arm span. The shark’s throat is only about as big as a human fist, but, mindful of the “minimum 3m from the head” protocol, I kick around to its side to appreciate the white spots and stripes flecking its fins and broad, dark grey back.

The sweeping sands of Coral Bay (Photo: CJ Maddock/Tourism Western Australia)

Even without the lure of whale sharks, Ningaloo offers superlative snorkelling and diving. On a trip with Coral Bay EcoTours, a 90-minute drive south of Exmouth, I snorkel with shoals of bright fish as well as a relaxed turtle.

Scuba diving is equally joyful. We spot sharks, rays, an octopus and a friendly and bizarre-looking batfish.

Forget bucket lists: I fully intend to return.

Getting there

The writer flew with Singapore Airlines from Heathrow to Perth via Singapore. Economy returns from £908, business returns – with a menu created by Monica Galetti – from £4,904, singaporeair.com. Qantas flies from Perth to Exmouth from £262 return, qantas.com

Where to visit

An all-day whale shark tour with Ningaloo Discovery costs A$550 (£265) including transport, ningaloodiscovery.com.au. A two-hour glass-bottomed boat and snorkelling tour with Coral Bay EcoTours costs A$98 (£47), coralbayecotours.com.au

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