You may also like these photo galleries
You join us on our pre-breakfast snorkel safari off Lady Elliot Island, sometimes known as "Manta Heaven", at the southernmost point of the Great Barrier Reef.
The previous day we'd dived one of the island's signature sites, the Blowhole. It had been exquisitely beautiful. Beginning, stunningly, with the Blowhole itself.
As soon as we'd made our way down to the end of the mooring line and achieved the required depth, our dive leader had beckoned us into this gaping cavernous entrance to a secret world.
With a pinch of the nose to equalise the pressure in our ears, we'd descended into an aquatic film set, feeling part of a nature documentary. Hey, David Attenborough, eat your heart out: how easy is this?
Look, there's giant potato cod nestling in the cavern's roof! See that school of trevally nestling as we emerge? What happened to the resident crayfish that is usually found here?
Our extended dive beyond the Blowhole had been memorable. Both white and black-tipped reef sharks; three species of turtles; coral trout. Plus, of course, the colourful coral formations themselves.
But manta sightings? Not a glimpse.
Disappointed? A little.
Which explains why at 6.30am, our party is on a manta mission. At dawn, we don snorkel and fins, and wade shin-high into the almost bath-temperature ocean. But this time, we have local knowledge on our side.
Last night we'd attended Secret Life of the Manta, the after-dinner lecture by Elena Hawke, Lady Elliot's resident marine scientist.
She'd recommended we head to Lighthouse Bommie – so named because it's just 50 metres into the reef from the island's heritage lighthouse.
Twenty minutes into the snorkel odyssey, things aren't hopeful. We've seen a few triangular indentations in the sand where stingrays have lain. Lots of vibrant coral. And enough colourful fish to generate another Finding Nemo/Finding Dory spin-off.
But again, no mantas. Then, as I'm being diverted by a green turtle paddling by on my right, a fellow snorkeller gives me one of those underwater diving signals that roughly translates as: "Look left, you idiot!"
And so I see my first manta. Small, perhaps five metres from wingtip to wingtip. The four of us watch its elegant, ghost-like progress as it shimmies through depths to unknown destinations.
I'm happy now. But this is just the beginning. Later, when we reach Lighthouse Bommie, a much larger manta is circling around the coral outcrop.
Its two horn-shaped cephalic fins, either side of its gaping mouth, seem to form a giant vacuum, hoovering up any attendant fish for a mid-morning snack.
But thanks to Hawke's lecture, we now all know the manta isn't making a meal of these fish – it is using them. This bommie is an underwater cleaning station.
Some of the symbiotic fish are maritime equivalents of dentists. All they have to do is feed on the plankton stuck in the manta's jaw.
The black-tipped butterfish, on the other hand, is literally a "bottom feeder", living in the manta's anus and giving what amounts to a perpetual colonic irrigation.
We watch this manta for perhaps 15 minutes as it goes through its fascinating preening procedure. Briefly, it is joined by two other mantas, all circling the bommie together like synchronised swimmers. When we finally snorkel back to shore for breakfast, we're ecstatic.
The reason our party is spending two nights here on Lady Elliot Island, followed by two more on neighbouring Heron Island, is because we're following the bubble trail of the world's most famous naturalist, Sir David Attenborough.
Now 89 and a widower with dodgy knees, Attenborough has just finished what may be his last documentary.
David Attenborough's Great Barrier Reef is a three-part series developed in partnership with Tourism Australia and Atlantic Productions, due to air on the ABC this year.
Obviously the reef also figures prominently in Tourism Australia's new global advertising campaign, There's Nothing Like Australia, which was launched in New York on Australia Day, highlighting this country's aquatic and coastal experiences. About 70 per cent of international visitors include such experiences during their trip here – though statistics show Australia is losing ground to South Africa, Hawaii and the USA.
The newly filmed campaign features more than a dozen experiences representing every Australian state and territory. As well as snorkelling on the Great Barrier Reef it includes a helicopter ride over the 12 Apostles, swimming in Sydney Harbour, kayaking through Katherine Gorge, driving on the beach in South Australia, cycling around Lake Burley Griffin, sailing around Rottnest Island and walking the recently launched Three Capes Track in Tasmania.
Attenborough has been a frequent visitor to the reef. Legend has it that the broadcaster took his first scuba dive on the Great Barrier Reef 60 years ago for Zoo Quest, the groundbreaking BBC TV series which made his name. He was astounded by what he saw underwater, later saying: "I can mention many moments that were unforgettable and revelatory. But the most single revelatory three minutes was the first time I put on scuba gear and dived on a coral reef." he said.
In an interview with London's Telegraph magazine, Attenborough said: "There's no equivalent anywhere else in the natural world of such splendour: all of these things moving through an architecture of coral. You never know what you're going to see when you turn the corner – it's far more obviously exciting and visually thrilling than, say, the tropical rainforest, which is the nearest biological parallel. In the rainforest they're all hiding, so you have to be quite a good naturalist to really see what splendours are there. But on the reef they're all on display. It's like the Christmas windows at Harrods."
In late 2014, he and his award-winning film crew returned to the Great Barrier Reef. Though he doesn't dive anymore, he filmed his famously erudite narration by the shore, in boats on the reef, and – we're told – in a semi-submersible submarine.
Pete Gash– former professional Moto-X rider, pilot, aviation entrepreneur, eco-warrior and majority owner of Lady Elliot Island – is quick to remind us Attenborough didn't come to Lady Elliot himself. But his film crew were on the island for days, getting footage of the mantas we've just witnessed.
Like its slightly more developed neighbour Heron, Lady Elliot is a tiny coral cay, an island of coral fragments surrounded by a turquoise halo of living coral below sea level. Both islands support small eco resorts which offer comfortable but simple accommodation and an emphasis on getting close to the nature of the Great Barrier Reef. That means diving, snorkelling and various activities arranged through the islands' education centres – reef walks, bird talks and lectures like Hawke's talk on mantas.
"We're not Hayman or Hamilton islands, and we don't pretend to be," Gash says of Lady Elliot. "People come here to Heron to get out on the reef, not lounge by the pool with a cocktail," echoes one of the dive staff at Heron as he hands out our snorkel equipment so we can see the collection of stingrays which gather under the island's jetty.
Of the two, Lady Elliot probably has the more interesting history. About 80 kilometres north-east of Bundaberg on the edge of the continental shelf, the tiny island (less than one kilometre wide) was first spotted by Europeans in 1816 when Captain Thomas Stewart named it after the ship – Lady Elliot – he was sailing from India to Sydney.
Subsequent mentions of Lady Elliot Island describe it as the equivalent of a modern bird sanctuary, replete with shearwaters (commonly known as muttonbirds), black noddies, oyster catchers and curlews.
But all that bird poop was the island's undoing. In 1863, guano miners moved in. Over the next decade, Lady Elliot was denuded virtually of all life. Trees, birds, plants were stripped as the Chinese labour gangs dug into centuries of accumulated bird droppings. The best stuff – white guano – was exported to the US to be turned into Civil War explosives. Lady Elliot became a wasteland.
Ten years later, in 1873, the first permanent lighthouse was erected on Lady Elliot. It's still there today, but superseded by the automatic, anonymous, solar powered tower beside it.
Gash has been running Lady Elliot since 2005. But he has been passionate about the island since he first saw it, visiting by boat with a few friends in 1979.
His predecessor, Don Adams, began the simple eco-resort and put in the landing strip which was opened by Queensland premier Joh Bjelke-Petersen in 1969. Today Lady Elliot remains the only coral cay along the entire 2000 kilometres of reef to have its own airstrip, with Gash's airline Seair Pacific running flights from the Gold Coast, Hervey Bay, Bundaberg and Brisbane.
When Adams founded the resort, Lady Elliot was still an environmental disaster. But there has been a huge recovery in the past decade under Gash.
Like Heron, Lady Elliot was one of the first of the Barrier Reef islands to be declared a Green Zone – meaning there's a rigidly enforced "no take" policy when it comes to marine life. Meanwhile on land, a team of enthusiastic volunteers has been planting native Pisonias, Pandanus palms and octopus bushes – which has encouraged birds to return. Some 88 species of bird can now be seen at Lady Elliot including the red-tailed tropicbird which is found on only one other island on the Barrier Reef.
As the most southerly of the Barrier Reef islands, Gash explains that Lady Elliot hasn't suffered from the disastrous run-off of fertiliser nutrients which have had such a negative effect on the coral and marine life further north. He's also invested heavily in solar power, reducing the resort's carbon emissions by 70 per cent and earning it Ecotourism Australia's advanced eco certification.
Though you can do a daytrip to Lady Elliot, most guests stay three or four days – submerging themselves in the reef activities. The rooms, capable of taking a maximum of 150 guests, are simple but adequate (mine had a lovely beach view), and the buffet-style meals are wholesome and filling.
Sadly, we are at Lady Elliot for only two nights, but Gash had arranged a spectacular departure for us.
We have to fly to Gladstone to catch Heron Island's specially designed catamaran for the two-hour crossing. But rather than take the direct route from Lady Elliot to Gladstone, Gash had told Dane, our pilot, to take us the scenic route.
It turns out to be one of the most beautiful and memorable flights of my life. Navigating by iPad and flying at just 1500 feet above sea level, Dane points out each new island or reef: "Lady Musgrave Island, Fairfax Islands, Bolt Reef, Masthead Island, Sykes Reef, Wreck Island ... "
From the air, each one looks like a gigantic turquoise and sand-coloured jellyfish. Some, like One Tree Island – with its scientific research station operated by Sydney University – are particularly distinctive with strange, haunting patterns formed in the coral like a painting in a contemporary art gallery.
Three hours later, we arrive at Heron on the Heron Islander. Two of us grab some snorkel gear for a quick pre-dinner adventure. The wreck of HMCS Protector – once one of the most powerful gunboat cruisers in the world – was towed here in 1945 to form part of Heron's breakwater. Barely 50 metres off shore, it's a magnet for marine life. This evening we see reef shark, turtles and up to a dozen stingrays of various descriptions.
The following day we dive two of Heron's signature sites – Coral Cascades and Heron Bommie and see exquisite coral teeming with fish. Yet the three creatures which brought Attenborough to Heron can be seen on foot.
The broadcaster stayed at the resort (now owned by US operator Delaware North), but spent most of his time on Heron at the neighbouring research station administered by the University of Queensland (island guests can do a complimentary tour of the facility).
Liz Perkins, the research station manager, says Attenborough talked at length to the scientists working on the station's long term climate change studies as well as experts on three of Heron's natives – the epaulette shark, the wedge-tailed shearwater, and the black noddy tern.
We're lucky enough to see an epaulette shark on an afternoon reef walk led by Sara Keltie, Heron's naturalist guide.
"Epaulette sharks are incredibly unique," she says, pulling one out of the knee-high water that partially covers the reef at high tide. She holds the metre-long creature in both hands to show us. "They can walk on land. If they get stuck in a rock pool when the tide recedes, they can walk onto the coral using their fins which act like muscular feet.
"So it was no surprise they interested David Attenborough. They can be found elsewhere in the Barrier Reef, but the great thing about Heron Island is that you don't have to go far to see them. Most days we'll see one on our reef walk."
The other strange thing about epaulette sharks, Keltie adds, "is that they can go with almost no oxygen for up to six hours at a time – they just go into a sort of semi-coma."
Attenborough and his crew weren't on Heron at the right time to see the annual turtle nesting and hatching parades between November and March. Visiting in November, we are much luckier. After dinner at the resort's a la carte Shearwater restaurant, we spread out in groups along the beach obeying the instructions Keltie had given us so as not to disturb the green and loggerhead turtles laying their eggs by moonlight.
The black noddy terns fascinated Attenborough because of their symbiotic relationship with the Pisonia trees which are plentiful and lush on Heron. As for the monogamous shearwaters, Keltie described them as "the clowns of the reef". It's particularly amusing watching them land at dusk. Because of their poor night vision, they simply curl up into a ball midair and plummet to the ground when they think they're close to their burrow.
Throughout the night, the shearwaters talk to each other in an eerie, ghost-like wail. For those of us trying to catch up on sleep, their chatter is irritating. But, as Keltie said, "What we have at Heron is the soundtrack of an Attenborough documentary."
Attenborough's final few hours on Heron will be something she never forgets, Keltie tells us. "This was the last stop of their filming trip. They finally got their last shot and David was done. That night they invited a lot of the island staff who had helped them to their wrap party.
"They set up a projector screen and showed Jurassic Park, which his brother Richard had starred in.
"I handed the guy sitting next to me some popcorn and realised it was David Attenborough.
"I remember thinking, 'I'm sharing popcorn on a beach with Sir David Attenborough watching Jurassic Park. What's ever going to top this?'"
The only public access to Lady Elliot Island is via aircraft. Seair Pacific operates daily flights from the Gold Coast, Brisbane (Redcliffe), Hervey Bay and Bundaberg. See www.seairpacific.com.au or 1300 473 247.
Most visitors arrive at Heron Island on the Heron Islander from Gladstone, $60 each way for adults. Alternatively a seaplane service operates from Gladstone, from $338 per person each way. See www.heronisland.com/Getting-Here.aspx.
Lady Elliot Island has a range of two bedroom suites, reef units suitable for couples or families, and safari-style tents. Until March 26, the resort is offering a two night turtle watching package from $563 per person twin share including return flights from Bundaberg or Hervey Bay, safari tent accommodation, buffet breakfast and dinner, and snorkeling equipment. See www.ladyelliot.com.au.
Or phone 1800 072 200.
There are more accommodation options at Heron Island - from a Beach House which sleeps four from $815 per person per night to the cheaper Turtle Rooms from $335 per person per night, twin share.
A three night Turtle Season package, until March 31 2016, starts at $160 per person per night, twin share including breakfast and snorkel trip. See www.heronisland.com. Or phone 1300 731 551.
FIVE MUST-SEE ATTENBOROUGH DOCUMENTARIES
LIFE ON EARTH (1979)
This landmark series set the bar for natural history docos. Highlights include the rare frog which incubates its young in its mouth, a slow-motion sequence of bats' wings in flight and Attenborough's encounter with gorillas in Rwanda.
THE LIVING PLANET (1984)
A study in how living organisms have adapted to their environment. The 11th of the 12-part series, The Open Ocean, saw Attenborough don scuba gear including a full faceplate which allowed him to narrate and be seen underwater.
PLANET EARTH (2006)
The most expensive natural history documentary ever commissioned by the BBC, it took five years to film and was the first to be shown in high definition. It was broadcast in 130 countries.
The reputed £10 million budget, four-year filming schedule and pioneering camera technology allowed Attenborough's team to record footage never seen before. Super high-speed cameras shooting 8000 frames a second slowed down dramatic moments invisible to the human eye.
FROZEN PLANET (2011)
This seven-part series focuses on life in the Arctic and Antarctic. The final episode (written by Attenborough unlike the rest of the series where he is merely narrator) is his personal statement on climate change.
FIVE GREAT BARRIER REEF FACTS
It's the world's largest reef system, consisting of 2900 individual reefs and 900 islands stretching over 2600 kilometres. Larger than the Great Wall of China, it is the only living thing that can be seen from outer space.
More than 400 different corals can be found on the Great Barrier Reef, a greater variety than any other reef in the world.
More than 1500 species of tropical fish make their home in the Great Barrier Reef, including humpback whales and sharks.
Among the 20 species of reptiles to be found within the reef are sea turtles and giant clams that can live up to 120 years.
The reef provides breeding and roosting habitat, feeding grounds and migratory routes for 23 seabird species and 32 shorebird species. Up to 1.7 million birds breed on the reef's islands and cays – more than 25 per cent of Australia's breeding seabird populations.
Steve Meacham was a guest of Tourism and Events Queensland, Lady Elliot Island Eco Resort and Heron Island Resort.
See also: Australia's other Great Ocean Road