My memory in midlife isn't what it once was – so I took a risk with a whale shark

‘Stop panicking,” my sister Liz reassured me as I clung to the duckboard of a heaving boat, my flippered legs dangling into the Indian Ocean. “Whale sharks only eat plankton.”

“A vegetarian shark? Yeah right,” I said through nervously chattering teeth, my goggles fogging. “No creature gets that big from eating seaweed!”

Above us, the spotter plane suddenly circled then dipped lower. Over the radio came a crackling message from the pilot to the captain – a 40ft juvenile male whale shark was in the vicinity. Our little boat veered left in a spritz of spray, sending me lurching sideways. As a big wave rolled under the boat, I clutched Liz in terror. “But what if I get seasick and turn green? The whale shark might mistake me for a bit of algae!”

“Actually, whale sharks eat zooplankton.” I looked up at a young woman who was beaming a megawatt smile down onto our little group of eight snorkellers. There was a high-spirited flick to her ponytail – the hair-do version of a cheeky grin. She looked like the kind of woman who has the Balinese words for “love” and “serenity” tattooed on her inner thigh, except she then introduced herself as our onboard marine biologist.

“Zooplankton, you mean, as in animal based?!” I trumpeted through my snorkel. Hailing from Australia, I have a serious shark phobia. Surely, if God had meant us to swim in the ocean, he would have given us shark-proof cages? There must be a reason fish never look truly relaxed. Could it be because something much, much bigger is always trying to devour them?

But before I could crawl at breakneck speed back to the safety of the deck, our perky biologist’s ponytail pinged up behind her like an antenna. The captain gave the signal and she shouted “Go! Go! Go!” A gentle nudge from her flippered foot and I was over the side. After splashdown, I peered into the depths and gulped. A thousand feet of sapphire blue sea stretched away into darkness below. My Darth Vader breathing accelerated so rapidly I thought my hyperventilating head might explode. But my fears were immediately cauterised by astonishment, because cruising towards me was one of the most massive creatures I have ever seen. With a whoosh, the magnificent whale shark glided gracefully by.

The behemoth’s luminous polka-dot pattern, as unique to each specimen as a fingerprint, strobed in the shards of sunlight, making it look as though he was headed to a disco. And wherever he was going, I wanted to go too.

“Swim!” our jaunty marine biologist instructed. Snorkels up like periscopes, we ogled through our goggles for a moment, then naturally fanned out on either side of this big, beautiful beast. For the next 40 minutes, we simply swam gently alongside, gazing with wonder at his pulsating, frilly gills, undulating tail and wide, grinning mouth. In a fugue of blissful astonishment, we accompanied this gentle giant as he made his steady, stately progress north along Western Australia’s Ningaloo Reef, nonchalantly noshing on plankton, roe, copepods and krill.

At one point I swam too far ahead and the whale shark’s massive slit of a mouth suddenly gaped in my direction. Just call me Ishmael, I gulped, nervously. Was I about to be hoovered up into that formidable Moby Dick-sized orifice? I darted back out of the way before I became an accidental hors d’oeuvre.

Before this encounter, the biggest creature I had ever seen in the sea was a bloated Russian oligarch, bobbing about the Med beside his superyacht. It’s always so tempting to harpoon one for scientific purposes, or rather porpoises. But nothing had prepared me for the size of a whale shark. The biggest fish in the sea, it can grow up to 65ft long. Its life span is thought to be more than 100 years. But apart from those few facts, these enigmatic ancient mariners are basically the Greta Garbos of the sea world; we know so little about where they mate and calve, or their routes.

But snorkelling beside this humongous filter feeder, entranced by his enormous gills, which sieve 6,000 litres of water an hour, in, out, in, out, I soon lapsed into a meditative state. Humans may be top order predators, but this experience was truly humbling. Dwarfed into insignificance, it was awe-inspiring to be transported into his shimmering, oceanic world.

Mesmerised, Liz and I could have swum on with him forever, but the whale shark suddenly angled his massive head towards the sea bed. His colossus body then tilted downwards into a slow, deep dive. We mere minions floating on the surface, watching this king of the sea disappear into the depths, until all we could see were a few pale polka dots shrinking into darkness.

It was only when I poked my head up and lifted my goggles that I took in just how far we were from land. So, why was I treading water in the middle of the pelagic wilderness? Because psychologists maintain that pushing yourself out of your comfort zone and taking risks improves cognitive abilities. Aged 63, do I need to improve my mental muscle? I dunno. Let me collect my thought. There are three signs of senility: memory deterioration and … wait … what were the other two? In other words, yes. And what could be more stimulating than swimming with a creature the size of a double decker bus?

My sister and I swam back to our boat which bobbed on the briny, 150ft away. Over a hearty lunch, we chatted excitedly with our fellow tourists, swapping impressions. Basically, the fish we had just encountered was so big, we dislocated our jaws describing it. There really is no other way to put it – we’d all had a whale shark of a time.

Situated between Perth and Broome, Ningaloo’s 250-mile stretch of crystal clear sea and pristine reef is regarded as one of the last great ocean paradises. The most endangered species here are actually humans with fewer people per mile than almost anywhere else on the planet.

Our hotel base, in the little town of Exmouth, is part of what locals call “The GAFA – The Great Australia F--- All”. But this splendid isolation means there is no pollution nor agricultural runoff to damage the beauty of Ningaloo’s exquisite underwater garden. This world heritage area also boasts the highest reliability rate of whale shark interactions: between 300 and 500 make their way here every year.

And mother nature has even more in store on the local awe-ometre. The next day, kayaking along the Coral Coast, we slipped into the silken sea to snorkel through iridescent atolls, ducking and diving with turtles, manta rays, dolphins and dugongs. Fishermen of yore thought these gentle “sea cows” were beautiful mermaids, which shows how long they must have been at sea!

At Five Mile Beach we watched enthralled as turtle hatchlings dashed into the moonlit sea. Rubbing their necks on the sand gives the turtles a magnetic imprint. Thirty years later, this internal sat-nav will guide them back here to lay their eggs. 
On Rottnest Island, we cuddled the world’s happiest marsupial. Ten thousand quokkas live on this little island of turquoise bays and sandy beaches, flashing goofy grins for tourist selfies.

In cosmopolitan Perth my sister and I cycled along the broad, beautiful river accompanied by flotillas of black swans. This was our swan song, literally, as our extraordinary trip was over. But this part of the world, from Rottnest and Fremantle right up along the Coral Coast to Ningaloo Reef, is so magnificent and magical that, just like those little turtles, it is imprinted into our psyches, ensuring we will return.

And it’s a promise that won’t be erased from my mind, now that I have sharpened my cognitive powers. As you age, your memory becomes so poor you sometimes forget you have a poor memory. In fact, I have only a vague recollection of starting this article. But swimming with Ningaloo’s whale sharks is simply unforgettable.

Essentials

Audley Travel (01993 838810; audleytravel.com/australia) offers a 17-day trip to Western Australia, including Perth, Rottnest Island, the Coral Coast and Ningaloo Reef, from £4,750pp, based on two people sharing. The price includes international and domestic flights, accommodation on a room-only basis, a seaplane flight to Rottnest Island, a hire car from Perth (with one-way fee reduction) and excursions including swimming with whale sharks