One minute we’re in chilly Melbourne, the next minute  – well, a quick two-hour flight – we’re stepping into Queensland’s balmy air.

In no time, we’re gliding out on the glass-like waters of Hervey Bay’s Great Sandy Strait on a sunset cruise.

Whalesong Cruises heads out all year in its purpose-built vessel on the lookout for dolphins, turtles and dugongs. From mid-July to September, it’s peak whale-watching season along the “humpback highway”.

“We don’t use radar,” explains Bec Greenshields, our host. “We just watch for spouting water.”

The humpback whales’ spout can shoot hundreds of metres into the air. We’re on alert but it’s the captain on the bridge who spots it first, and sure enough, we then see our first whale, breaching out of the water and its immense body crashing back down.

Humpbacks make their annual 10,000-kilometre migration from the icy Antarctic to Queensland’s tropical waters to mate and give birth. They then head south with their calves, spending time feeding in Hervey Bay’s warm, sheltered waters.

So many whales pass by, that from mid-July Whalesong has a money-back guarantee if you don’t spot one.

We spy a storybook pod of dolphins playfully arching over the water. Then suddenly, the sky, which has turned a brilliant orange, is flecked with thousands of – what? “Fruit bats,” says Bec. “They fly over to feed on the flowering trees on K’gari and then fly back to sleep on the mainland.”

Short, sweet flight

Early next morning, we too are headed for K’gari (formerly Fraser Island). Great Ocean Helicopters’ jaunty little yellow flying machine – it seats four, but it’s definitely tiny – whizzes us in VIP style across the strait’s serene waters to the world’s largest sand island.

As we swoop in we can just spot Kingfisher Bay Resort, tucked amid pandanus and gum trees.

The Butchulla people are the traditional custodians of K’gari (pronounced GAH-ree, meaning paradise), a UNESCO World Heritage site. It’s a unique blend of wetland, forest and ocean ecosystems – a mecca for nature-based activities.

Eco and active

The sprawling eco-resort is set back a few hundred metres from the beach, leaving that stretch of bush for sugar gliders, echidnas, swamp wallabies, bats and other mainly nocturnal species.

There’s a busy – even hectic, if you decide to join in everything – list of events, from ranger-guided canoe paddling and bushtucker walks to bird-watching and archery. Lazing at the pool is another option, but not for us.

We’re on a four-wheel drive Explorer Tour to check out some of the island’s iconic sights. Mark Canham, our driver, ex-Australian Army and a fount of enthusiasm and information, appears to drive our bus effortlessly along corrugated sandy roads through jungly, subtropical rainforest, then along remote beaches and steep, rutted tracks, all the while citing facts, figures and the occasional dad joke.

Dingo alert

We learn that dingoes’ fur-lined ears give them acute hearing. They don’t bark, they howl like a wolf. They’re lean but powerful and can run at up to 60km/h. Mark thinks they pretty much go about their own business (dingo alert – don’t touch or feed them!).

As we zoom along the beach, we see a lone dingo sunning itself. We pull alongside, but the dingo doesn’t even budge. Talk about cool.

Apparently four of Australia’s five most venomous snakes can be found on the island (but there’s nothing to worry about, Mark assures us!).

About 350 coastal and migratory bird species have been recorded here and we see flocks of plovers scurrying nervously along the sand, a white-bellied sea eagle soaring overhead and several white-faced herons stalking the shoreline on their gangly legs.

The east coast’s famed 75 Mile Beach – officially a national highway –  is a sublime sweep of pale sand, washed by the endless blue–green sea and crisp white breakers.

We stop near the Gram-perfect, rusting hulk of the SS Maheno shipwreck, and the crystal-clear waters of Eli Creek, edged by pandanus and flowering banksias.

Visitors pull up in their  “fourbies” and unpack picnics and ocean-fishing gear. A light plane lands on the beach (yes, it’s a runway too!). Children (and everyone else) drift lazily on floaties in the stream.

At Pile Valley we follow a heritage walking trail, the sun filtering through a canopy of towering Kauri and Satinay trees, with gin-clear water rippling along the winding creek bed.

Next stop is Boorangoora (Lake McKenzie), one of more than a hundred freshwater lakes on K’gari. Its pristine blue waters are rimmed with silky, white sand. A quick dip is a right of passage, before heading back to the resort.

After cocktails at the jetty’s laidback Sunset Bar, it’s dinner at Sand and Wood, where tables with flickering candles overlook the resort’s pools and leafy garden.

The food – seasonal, regional – is inspired by native bush tucker, with Asian and Pacific flavours. From simple fresh-shucked oysters, grilled prawns and boat-fresh barramundi to inventive fare – such as crispy lotus root in a tamarind sauce – it hits just the right note.

We stroll along the boardwalk to our apartment, which overlooks a lily pad-strewn lake. From our balcony there’s a positive wall of frog sounds and a dark, starry nightscape. A little bit of paradise.