One thing I notice quickly in and around Cairns is how few people are hunched over their cellphones.

Instead, devices are put away to rediscover that thrill of the physical world - the taste of salty sea air as we speed out on the sea, or the faint, hypnotic buzz of insects as we paddle down rivers winding through mountains.

Stripped down to the basics is where I find myself as my team gears up - with helmets, life jackets, thermal tops and copious amounts of sunblock - for a day-long whitewater rafting ride about 10 to 15km down the Tully River with rafting company Raging Thunder (www.ragingthunder.com.au).

Cellphones are quickly forgotten since signals are lost minutes into an hour-plus ride out of the city to the river high in the mountains.

Trip leader Marty Coates, 48, tells our busload of adventure seekers to take only the basics. Of our valuables, he good-naturedly cautions: "If you would like to see it again, leave it in the bus."

Because of a daily water release from an upriver hydroelectric station, whitewater rafters are guaranteed an adventure, even during the dry season. Mr Coates adds: "You won't be seeing any swans today."

In placid water, with misty mountains in the distance, our team of five practises newly learnt rafting moves with our guide Darren Nunn, 46. And then we are suddenly off, with Dazza, as his colleagues call him, shouting commands.

At the first rapid, nicknamed Alarm Clock - aptly for the wake-up call it gives - everyone gets drenched in icy river water as the raft bounces over the rocks.

It is hard to think of anything except his instructions - "One-two, one-two, forward paddle!" - when I'm faced with rushing water and rapids the guides have aptly named Oh Sweet Jesus or Scales Of Justice.

Raging Thunder, it seems, has a knack for hiring cheeky, chatty lads as guides - Dazza playfully manoeuvres the raft under a waterfall and, for about 10 seconds, I could hardly hold up my head as litres of water pound down on my helmet and batter my arms. Dazza stays dry.

Under the guides' watchful eyes, the ride feels safer than one in a theme park.

But do not get complacent.

The adrenalin junkie in me rears its head and makes me lean out further than I should have at a rapid and a sinking feeling overcomes me as I realise I am about to fall out of the boat.

Which I do. The unscheduled plunge into the water - and somehow under the raft - promptly brings me to my senses, even before Dazza heaves me out seconds later.

Somewhere inside my belly is a gulp of the Tully river, a souvenir.

For the corporate warriors everywhere, tropical north Queensland is also a place to step out of the comfort zone. Exchanging air on the surface for a regulator and oxygen tanks to see the Great Barrier Reef, for instance.

No diving licences necessary, the visitor can pick up the basics of an introductory dive in the time it takes to reach Agincourt Reef, an hour or so by fast catamaran from Port Douglas, a smaller beach town about 60 to 70km from Cairns.

Cruises to see the Great Barrier Reef operate from both Cairns and Port Douglas, to name two.

Out on a platform in the middle of the sea, the hardest thing is staggering down the steps of the platform carrying the tanks, weights on our belts and other equipment, dive instructor Jai Otto, 38, promises.

The Quicksilver Group (www.quicksilvergroup.com.au), which I am travelling with, has operated cruises to the Great Barrier Reef since 1979.

Nerves, panic and mini The Godfather moments of "sleeping with the fishes" evaporate when I see a reef shark pass by seconds after we descend 10m into the water.

Mr Otto holds my dive partner and me by the hand, guiding us in a surreal exploration during which the only sound I hear for the next half hour is the escape of air as I breathe in and let bubbles out.

So my attention is squarely on the underwater scene: among rock and boulder corals and wavy soft corals, I spy tiny clownfish like in a scene out of Finding Nemo, a turtle, giant clams perched on the sea floor and, the icing on the cake, a huge wrasse twice the length of my arm.

Mr Otto says later that the staff have named the fish Chunk because a nob of flesh is missing from its body.

If you prefer to stay dry, simply find a corner of the floating platform or head for the top deck of the boat, where you can enjoy the sun, the cool nip of Southern Hemisphere winter air and kilometres of sparkling blue water, interspersed with glints of coral from the Great Barrier Reef.

Another challenge to try: Take a day trip out to the World Heritagelisted Daintree Rainforest in Cape Tribulation to go "jungle surfing" - ziplining from tree to tree, dangling as high as 22m above the rainforest floor.

It is a long ride to reach the Jungle Surfing Canopy Tours (www.junglesurfing.com.au) nook but, all too soon, it is time to face our fears.

We are buckled into harnesses and helmets and told not to fiddle with or try to undo the cables we are strapped to. There is a funky whiff on my harness - is it the smell of trepidation, I wonder, peering up at the lines high in the trees.

The guides try to tell our group interesting facts about the forest - how one of the plants naturally secretes cyanide in its leaves, for instance - but all we can chat nervously about is how fast we are travelling on the ziplines, or the funny names written in marker on the helmets the crew chose for us. A friend is Catwoman; I am Pippi Longstocking.

But I feel more like Tarzan as we fly through the jungle at one point upside down and at a thrilling 45kmh - screaming "I love my job! I love my job!" - as we speed back to the ground.

Back at the base, we return the gear, but a distinctive smell lingers on our clothes.

I recognise it now: It is the smell of a challenge met and a good day out.

Now, that is something to tweet home about.

•The writer's air travel was sponsored by SilkAir, while Tourism and Events Queensland hosted the ground activities.

•Go to https://goo.gl/xZqKuo to see where the writer went.

Five other things to try

1. A day trip to Kuranda

This village (www.kuranda.org) surrounded by rainforest is a calming day's retreat where you can enjoy a cup of coffee and pecan pie at Petit Cafe, then wander the markets full of interesting art and handmade souvenirs.

You can drive or take the cable car or Kuranda Scenic Railway (www.ksr.com.au) from Cairns.

If you take the Skyrail Rainforest Cableway (www.skyrail.com.au), a 45-minute or so cable-car ride, take advantage of the free short nature tours, led by rangers, who will also show you what to do if you run into a cassowary in the rainforest.

Passengers who opt for gold class on the Kuranda Scenic Railway will enjoy a platter of delicious local cheese, dip and dried fruit, among other snacks.

Cable-car and rail package combinations are available, with fares starting from A$50 (S$50.90, one-way, adult).

2. Learn about the Rainforest People

They are the Tjapukai, or people of the rainforest, who used to live where Cairns and its surroundings now are, for 40,000 years.

At Tjapukai Aboriginal Cultural Park (www.tjapukai.com.au), you are taken back in time to see how the world, according to the Tjapukai, was formed from the breaking apart of a cassowary egg.

You will learn about traditional medicine, music and dance, as well as how to throw a boomerang and spear.

You can also sign up with other operators, such as Culture Connect (www.cultureconnect.com.au), for day trips to Janbal Gallery in Mossman, where you will learn about Aboriginal art and can paint your own; or to meet the Cooya brothers, two Aboriginals who will teach you how to spear fish and mud crabs in the mangroves for your lunch.

3. Cuddle a koala

Koalas possibly have the best working hours in Australia.

They work just 30 minutes a day, for three days, before getting a full day off. And the clock starts the moment the zookeeper carries them off their perch in the trees.

There are at least two places where you can carry one: Kuranda's Koala Gardens (www.koalagardens.com) or Wildlife Habitat in Port Douglas (www.wildlifehabitat.com.au).

If you do get a chance to meet them, notice how your fingers will come away smelling of eucalyptus.

The male marsupials have a scent gland on their chest and emit the smell of the foliage they devour.

4. Enjoy a free barbecue

The Cairns waterfront is dotted with electric barbecue pits and shelters, which casual users can use for free.

Simply take along your choice of grub - a nearby Woolworths Supermarket will have meat and produce. When you are done, clean up after yourself.

The terrific scenery of mountain ranges, or seagulls swooping along the water, is a given. Details of where the barbecue grills are can be found at www.cairns.qld.gov.au.

5. Putter around Port Douglas

Port Douglas (www.visitportdouglasdaintree.com) is a quieter beach town with a more laidback vibe than Cairns, great for a couple's getaway. Four Mile Beach has fine, sparkling gold sand and the marina is picture perfect.

It is a one-hour drive from Cairns, along a winding but scenic coastal road. Do not miss the Ironbar restaurant's (www.ironbarportdouglas.com.au) entertaining nightly cane toad races.