Dive of discovery off the Great Barrier Reef
I roll backwards off the pontoon boat and sink into the ocean depths. Fresh air and blue sky are forgotten as I descend into a silent world to meet whatever lies beneath.
Settling on the fine white sand at 23 metres, I'm within sight of a kaleidoscopic coral reef outcrop known as the Lighthouse Bommie, so named because it's straight out from the old lighthouse on Lady Elliot Island, the southernmost island on the Great Barrier Reef.
I'm torn between conflicting emotions. Being suspended in a weightless state in crystal-clear, tepid water, gives me a comforting back-to-the-womb feeling. But knowing that giant marine mammals are lurking in this vicinity brings a heightened state of anxiety.
I'm conscious of a high-pitched sound, the hauntingly beautiful song of a humpback whale somewhere out in the ocean. Suddenly I catch a glimpse of a sleek, menacing silhouette at the periphery of vision. A 3m white-tip reef shark circles the bommie, scattering the resident tropical fish, before vanishing into the blue.
This is an ecosystem of big muscle fish on steroids. When a giant manta ray arrives my heart leaps, as a great white blanket of underbelly passes straight overhead. The 4m wide monster hovers over the bommie, where it is instantly besieged by an army of hyperactive cleaner fish, the barbers and groomers of the reef.
In this undersea metropolis, the Lighthouse Bommie is Grand Central Station, the foremost fish-cleaning base on the reef. The manta ray hovers like an inter-galactic space ship while the assorted nibblers remove every trace of dead skin and parasites from his mouth and gills. The stealth bomber of the seas then makes a sweeping turn and vanishes into the gloom.
Witnessing this cameo of life beneath the waves makes me realise that inner space is a parallel universe as diverse and colourful as our own. The 1500 fish species on the Great Barrier Reef, the whales, dolphins, manta rays, dugongs and the 4000 species of molluscs live their lives in an ordered way with the same degree of connectedness and symbiotic relationships that humans enjoy.
The submarine city certainly has all the colour and variety of an earthly metropolis. The scroungers, suckers, pickers, biters, scavengers and devourers inhabit a coral jungle. Some are timid and take shelter in the nooks and crannies of the reef.
I particularly love the impish little Nemo of Hollywood fame. The tiny fish coats its body with the same mucus as its host anemone. The host has stinging tentacles with enough toxins to kill a small fish. When Nemo brushes against the blind anemone it registers as one of its own feelers.
Invariably, I find myself drawn back to the Clownfish Hyatt, a coral outcrop festooned with waving anemone feelers dotted with the cute little orange faces peering up at me. Remarkably, they are bold enough to nip my fingers and even dart up to my mask.
Moving in, I examine the coral outcrop closely but cannot see the clever little polyps that are the architects and builders of the Great Barrier Reef. It is astounding that the largest living thing on earth, the only structure visible from space, is the work of builders no larger than the head of a pin.
Trillions of tiny jellyfish-like coral polyps form a thin living veneer on the surface of a solid limestone foundation of dead corals that is over 2 million years old. The plucky little mites beaver away over their short lifespan, sustained by nightly feeds of zooplankton, each polyp adding a few more grains of limestone when they shuffle off the mortal coil.
Like their human counterparts all these undersea creatures are adaptable and resilient. The parrot fish sleeps in a cocoon of spun mucus, which hides its tell-tale smell from predators. The cuttle fish changes its colour and texture at will and has two eyeballs in each eye to focus on close and distant objects simultaneously. Survival in the deep requires super ingenuity and a large dose of luck.
As I continue to circle around Lighthouse Bommie I encounter more and more of the multi-coloured inhabitants. There are bright yellow angelfish with sweeping tails, flighty butterfly fish, cheeky-beak parrot fish that dart up to my mask in a mock attack and, my personal favourite, the gorgeously attired comedians known as harlequin tuskfish.
It's easy to lose yourself in this watery realm as the senses become fully engaged with the marine life. I'm swimming along an opening in the reef that is a main thoroughfare. A shimmering mass of big eye trevally, cautious and alert, are drifting slowly down the current navigating the passage like a convoy of VIP limos.
It's clearly not rush hour. A swarm of fusilier fish, moving in concert, are flowing along the reef wall like a river of liquid mercury. As I approach they instantly divide, allowing me to pass. Then they flow back together in one fluid motion as if choreographed by some unseen hand.
A large green turtle emerges from the gloom, paddling along at a leisurely pace, content in the knowledge that he has 100 years to complete his life's work.
Next I spot the big boys lurking in the shadows. Maori wrasse with intricate moko-like markings on their face lie motionless like metro line commuters waiting for their train.
The city dwellers on the reef have many roles to play. The big boys lord it over the reef as the predators. Pelagic baitfish and fusiliers form huge schools for their own protection. Marauders like eels and scorpion fish hunt under cover of darkness. Grazers like wrasse and parrot fish feed on sea grasses, and camouflage fish like blennies and sea horses blend into their surroundings and lie low.
When the full moon lights up the ocean in September each year, the city stages a reproduction carnival that is even more colourful than a Hero Parade. Entire reefs of coral polyps simultaneously eject a multicoloured shower of egg and sperm clusters in a unique upside-down snowstorm that drifts far and wide.
This is carnival time for whale sharks and other krill and plankton feeders, which cruise main street with wide open mouths. It sparks off a feeding frenzy for many species.
When my dive ends I feel exhilarated. Our dive group recounts stories of our undersea adventures. Then realising we are very hungry we enjoy the smorgasbord of fresh fish fillets, mussels, scallops, salads and tropical fruit laid out on the buffet table.
I can't help feeling that we're emulating the hungry citizens of that colourful city beneath the waves.
GETTING THERE Lady Elliot Island Eco Resort is a 40 minute flight from Hervey Bay Airport, which can be reached by Queensland Rail's Tilt Train, the most modern passenger train in Australia. It's a 3½ hour trip at a steady 120kph in a carriage that tilts imperceptibly on corners to smooth the ride. The island can also be reached by air services from Bundaberg, Sunshine Coast, Gold Coast and Brisbane.
STAYING THERE The island's beachfront bungalows have a capacity of 140 guests in a pristine, tranquil setting with views over the fringing reef and stunning visibility in the water for snorkelling and diving. Guest packages can include; dinner, breakfast, lesson in snorkelling, use of equipment, a glass-bottom boat tour and a marine walk. Day trip packages are also available.
The writer travelled to Lady Elliot Island courtesy of Tourism Queensland.