We’re standing on sand dunes at the end of a hot December day. The light’s fading fast and a thin crescent moon is rising in the clear sky. It’s still really hot; hot enough to dip in the ocean. But nobody does – not because it’s stinger season now, but because we’re here for something better.

Here on Magnetic Island in Queensland, everyone’s a volunteer and everyone’s local except me. There are kids in school uniform, parents who’ve come from work, a retiree, a CSIRO scientist, a marine biologist called Paul, and an off-duty park ranger. We take turns peering into a blue plastic bucket. Now it’s my turn. Inside is a batch of freshly hatched green sea turtles. Their easy exit from an underground nest was blocked by vegetation, so these volunteers have dug them free.

Paul pulls one out and it wriggles between his hands, so tiny and lively. The next moment, it’s hurtling down the thick golden sand of the beach with its brothers and sisters, towards the gently lapping waves. People are releasing them one by one. The baby turtles move so fast they might take off and fly like whirring cicadas, instead of entering the sea.

There are oohs and aahs and clapping and lots of smiles as each hatchling dives down and disappears. We wait a while, carefully watching the water’s edge, hoping they’re all safely on their way. Later, Paul tells me each of these green turtles has just a one-in-a-thousand chance of surviving to maturity. Now, we’re focused on just one of these – it’s washed back up, tried to swim again and failed, and has run out of puff. It goes back in the bucket, which I hold carefully on my lap as we drive to the hospital established and maintained by a larger group of volunteers, the Magnetic Island Network for Turtles.

If this runt of the litter survives the night, it will get a revival injection and hopefully stand a chance. Nearby are adult turtles well into recovery. One is decades old and moves slowly; it came in with an impossibly mangled shell, maybe bitten by a shark. Another’s younger and friskier – it was rescued with “floating syndrome”, caused by a gas build-up after a turtle ingests marine debris such as plastic, which stops food being properly absorbed. This turtle splashes and bangs excitably against the walls of its circular tank, and pokes its nose inquisitively above the water in my direction after sizing me up. Another survivor now seems to be practising a healthier kind of floating. It completely ignores me, makes balletic arcs with its flippers, and is a lot more zen.

I’d recently flown from Tasmania to Queensland, years after a memorable and moving encounter with a cheeky turtle while swimming in a coral canyon on the Great Barrier Reef. This time I headed to Magnetic Island, my visit starting with a day trip back to the reef. For a few hours, we sped away from the island, on a boat that had suspended operations when Queensland’s tourist industry was smashed by Covid border restrictions. This was its test voyage just ahead of the 2021-22 summer season. We were a random mix of locals from the island and nearby Townsville, interstate visitors like me taking advantage of the quiet before the storm of imminent border openings, and international travellers stuck in Australia since we closed to the world in March 2020. So there I landed – suddenly snorkelling with a 20-something exile from Salzburg in a remarkable open aquarium.

It was wondrous, floating in these warmest of seas with those tropical fish in sparkling schools and seductive pairs, and that amazing blue-and-peach-coloured coral beneath us. But part of my heart couldn’t help sinking – where’s that turtle?

The next day, I walked for hours in the baking heat with borrowed snorkelling gear and a stinger suit, through the national park on the island and its sleeping clusters of koalas, to beaches to which the road’s now closed. First stop was a bay ringed by hoop pines and renowned for turtles. The spectacular beach was empty. I sat in the shadow of granite boulders and ate my packed lunch, then set out swimming to the closer reef. As I moved towards a party boat nearby, now motoring back to sea, someone shrieked – “WE JUST SAW A GIANT TURTLE!” I guessed they did, but it swam away, and the engine noise meant I wouldn’t find it anytime soon. So I kept walking to other beaches.

Eventually I landed at Radical Bay, where I now know in the 1980s there was a resort with a disco playing until dawn, which isn’t there any more. It is wild land earmarked for a luxury property development that now seems to have failed. Conservationists still hope to buy it back for those elusive koalas and, I hope, visitors like me who want to float away gently from our daily lives to find something very much better – like majestic sea turtles.

I didn’t get to meet any turtles face-to-face in the seas near Radical Bay that day. But I hope to return sometime soon and try my luck again.

Meanwhile, I’m left with a special new memory: the sweet surprise of encountering that squirming hatchling – rescued in a bucket – which might have lived until morning.