Colourful coral garden. Photographer: Allyazza.

On an isolated seamount more than 300 kilometres from Cairns sits Osprey Reef, a jewel of the Coral Sea Marine Park. Its breathtaking corals, plummeting drop-offs and crystalline waters make this one of the best tropical dive sites in the world.

In contrast to the more sheltered Great Barrier Reef, Osprey Reef is truly wild and remote.

But for the many rare, beautiful and strange creatures that return here year after year or ride past on the south equatorial current it’s an oasis in the vast, tumultuous ocean.

“… an oasis for living creatures of all kinds.”
~ Sir David Attenborough ~

Did you know?

Osprey Reef is vast and grand.

Its exceptional architecture, with vertical walls, drop-offs and swim-throughs, is the summit of a great mountain that rises sharply from the ocean floor.

A combination of light, temperature and geological conditions support strikingly different plant and animal communities at different depths.

Osprey Reef is 2000 metres high: the reef sits atop an underwater mountain rising almost vertically from the ocean floor.
Underwater visibility is 30 metres to 60 metres: diving at Osprey is extraordinary.
Osprey Reef is almost 30 kilometres long and over 180 square kilometres in area, one of the biggest reefs in the region.

Lost worlds

In 2009 a team of researchers from Australia and Germany launched the Deep Down Under expedition, which sent remotely operated underwater vehicles to undiveable depths at Osprey Reef.

Among the otherworldly discoveries were:

a deep-sea fish – the sea toad, previously only found in South America
gardens of plant-like creatures, some new to science, including stalked sea lilies and glass sponges that would have dominated the ocean tens to hundreds of millions of years ago.

Explore it for yourself

At dive sites like North Horn, Admiralty and False Entrance you’ll find walls stepping down to 1000 metres, caves and grottoes to explore, and overhangs covered in huge soft corals.

Close encounters with schools of trevally, giant potato cod, green turtles, moray eels, octopuses, and a variety of sharks are all but guaranteed.

Osprey Reef is for experienced divers. Most sites can be dived year round with Coral Sea live-aboard dive expeditions.

Shark heaven

While it’s home to the world’s third-smallest fish, the stout infantfish, Osprey Reef is more famous for sharks.

sharks Sharks. Photographer: Allyazza

Grey reef whaler sharks and whitetip reef sharks are abundant year round.

At North Horn, divers often see majestic silvertip sharks. In cooler months, scalloped hammerhead sharks aggregate off the coral reef walls.

Manta rays can sometimes be found at their cleaning station at Round the Bend, and big-eye trevally, barracuda and black marlin cruise the surrounding waters.

One of the most extraordinary residents is the ancient chambered nautilus. Almost unchanged for 500 million years, it’s considered a living fossil. Its iconic spiralling shell is a precise buoyancy device, much like the dive tanks of a submarine, enabling nautilus to travel from their deep water homes to feed in shallow waters at night.