Probably the most alarming thing about spending the night in the middle of the Great Barrier Reef is not the fact you're 40 nautical miles from land, but the realisation that you can barely hear the ocean, even though you're basically lying on top of it.
All I can hear from my comfy swag under the stars on the pontoon is the wind and the odd creak from this clever structure, Reefworld, which has been anchored next to Hardy Reef for 20 or so years.
At 3pm the eight other "Reefsleepers" and I waved off Cruise Whitsundays' luxury catamaran Seaflight, and the 280-odd passengers and crew we'd spent the day snorkelling and scuba diving with on the reef. We couldn't wait to get this tiny slice of the 2300km-long natural wonder all to ourselves.
The three-hour ride out to Reefworld, the cruise company's private facility, through the 74 beautiful islands that make up the Whitsunday Islands National Park, had flown by, with lessons on how to snorkel and dive, health checks and safety briefings, morning tea, and information about the reef.
Once we left the calm of the national park and entered the open waters of the Coral Sea shipping channel, Seaflight started rolling about in the waves, and the crew handed out sick bags, as many lost the morning tea they'd just scoffed.
Luckily the ocean was flat again by the time we tied up to the pontoon, in a deep river tunnel on the reef wall adjacent to a postcard-perfect expanse of turquoise water.
Reefworld is basically a large floating barge with showers, toilets, a sundeck, staff quarters and kitchen, a shop, an underwater viewing chamber and an area for divers. Several metres away is a second pontoon used for weddings, and there are two helipads nearby.
All snorkelling and scuba gear is provided, and optical masks are available.
It's stinger season (it runs from November to May) so we don "stinger suits" (light wetsuits) to lessen the minute chance of running into one. The stingers, irukandji, are tiny and not deadly, but an attack is very painful and causes muscle cramps and breathing difficulties.
I've signed up for an intro scuba dive, A$119, ($122) and have a weight belt and heavy tank added to my get-up before I descend to a semi-submerged platform and practise breathing for 15 minutes under the luminous aqua water.
And then we're off - dive leader Taylor grabs my hand tightly and leads me and another rookie to the reef.
The water temperature is 27C, the visibility 8m-10m. We pass vibrant purple, orange and teal clams, multiple shades and varieties of coral, and hundreds and hundreds of brightly coloured fish with silly names: foxface rabbitfish, yellow-tail fusiliers, spotted sweetlips. It's busy down there. I feel disoriented but exhilarated as we dive to a depth of 8m during our 30 minutes, and am grateful for the clever guide rope system, which reassures me that my home base is within reach.
Later, my first real snorkelling experience is just as much fun as the diving, but gets better when the tide is low - the coral is so close to the surface that in some places it pokes out of the water.
The current proves quite strong along the reef wall, but there are a couple of rest stations on the rope system and usually at least two lookouts on duty, so it's hard to get into trouble.
Of the 1500 species of fish that call the Great Barrier Reef home, I can identify about 10, including the small blue damselfish that dart about in unison in large schools, and the majestic Maori wrasse. The crew chuck pellets of food in the water near the snorkellers to whip the fish into a frenzy; the fish seem unperturbed by 200-plus humans in their midst.
Apparently the odd harmless reef shark pops by from time to time but the scariest fish I see is George, the 3m-long giant grouper who's been hanging around these parts for 30 years. He's so special he has his own open area of the pontoon, where he's often visited by several girlfriends. Skye, our Reefsleep host, tells us later that one of the crew plays the saxophone to him because he likes the vibrations. Anything to keep George happy: I imagine he's the grouper equivalent of a grumpy old man.
If you've had enough of the water, there's plenty of other stuff to keep you entertained. An on-board masseuse works her magic in the Harmony Hut, there's a large underwater viewing chamber, shuttle tenders take people to the helipads for scenic flights, and every half hour there's a 25-minute trip in a semi-submersible submarine that travels along the reef wall with live commentary.
But that 3pm departure of the day-guests can't come soon enough for me and the other Reefsleepers: a couple from Melbourne, a mother and daughter from Sydney, two Taiwanese blokes, and a young English couple, Kyle and Gemma. There are also four crew, led by Skye - who does everything from manning the barbie to serving the drinks, while fielding questions about the reef and its fishy inhabitants.
As we were sitting around chatting and watching the splendid sunset, Kyle got down on one knee and asked Gemma to marry him. Cue much excitement, congratulations and Champagne, then the happy pair disappeared for a romantic dinner for two with the fishes, which the staff had set up in the underwater viewing chamber. We got so carried away with the moment I would have married George the grouper if he'd proposed right then, even if he is an old grump with several girlfriends.
By the time it's time to hit the sack, each swag has been set up on the top deck with a comfy mattress and linen.
It's clouded over so there are few stars, but the moon is full and bright. The absence of water-related noise has one good result: middle-of-the-night loo visits are not an issue.
After breakfast we get a few more hours of the pontoon to ourselves, then huddle together as Seaflight ties up once again - we feel quite territorial. There aren't as many people today but it feels like a invasion after almost 20 hours of peace.
Hanging out with chunky in the deep
As soon as I heard about Chunky, Charlie and Chip, I was eager to make the acquaintance of at least one of the three green sea turtles that regularly feed off the algae and seaweed growing on the Reefworld pontoon.
We were contemplating another snorkel when someone spotted Chunky. We suited up to join him, and spent terrific moments cruising with him.
I'd assumed he was called Chunky because he was a porker, but the poor old fellow was missing a huge hunk of his shell - either as a result of a shark attack or a boat collision.
We saw him the next morning at breakfast time when he popped by for another feed. Considering Chunky and his pals are an endangered species, it was a privilege to hang out with him.
Air New Zealand flies daily to Brisbane. From there, you can fly to Hamilton Island or Proserpine on the mainland.
Cruise Whitsundays sails to the reef from Airlie Beach (three hours) from Hamilton Island (two hours). Reefworld's Reefsleep is A$425pp until March 13, A$440 from April 1 for a king single or a double swag. cruisewhitsundays.com queensland.com