Australia Diving the Great Barrier Reef
Situated nearly 350 km away from Cairns, Osprey Reef is the most northerly of the reefs in the Coral Sea. It is separated from the continental shelf by a deep water trough and is regarded as one of the premier Great Barrier Reef dive liveaboard destinations, both for the visibility that it offers and the big fish action. The remoteness of Osprey Reef is a highlight in itself, where you will often find yourself far removed from anything that isn't wet and colourful.
Roughly oval in shape, Osprey Reef consists of a lagoon area, that is only 30m deep, but within 1 km of the reef the water shelves to 1,000m deep. This creates the perfect meeting ground for huge amounts of pelagic action including the famous shark feed at North Horn. The reef is in pristine condition with spectacular colourful soft corals that often exceed 2m in height. Shoals of pelagic fish and amazing walls will leave you wanting more no-stop time.
Diving in Australia at Osprey Reef, you will marvel at the sheer size of the gorgonian fans and catch sight of marine life such as green and loggerhead turtles, both of which are listed as being conservation dependent. Chances of encountering a manta ray or an eagle ray are good, as these are regularly seen in the area thanks to the reef acting as a huge magnet, drawing in vast amounts of marine life from the surrounding blue.
Not to be missed here is the resident shark population whose large numbers ensure that these adrenalin-filled wall dives will be among your highlights whilst scuba diving Australia. North Horn is the spot where these enduring memories are made. Against a backdrop of healthy reefs with large gorgonian fans and large pelagics in the blue, is where a famous shark feed takes place. You can expect to see, from you natural amphitheatre seat, grey reef sharks, silky sharks, and possibly even silvertips and hammerheads in a feeding frenzy which will make the hairs on your neck stand on end.
Also seen at Osprey Reef are some of the big-ones such as whale sharks, beaked whales, sperm whales, bottlenose dolphins, sailfish and marlin. You may be lucky enough to have these visiting whilst you are enjoying your Great Barrier Reef diving, but regardless, you will still get to enjoy the huge schools of barracuda and tuna.
Dive Site Descriptions
Admiralty - Osprey Reef is generally considered to represent the best diving in Australia's Great Barrier Reef area. Since it is further offshore and not part of the continental shelf it enjoys clear and rich waters, 2 key factors needed for excellent diving conditions. Admiralty showcases both factors well.
There is a steep drop-off where nutrient-filled currents rise up against the solid structure making the area rich in food and therefore rich in feeders. Visibility here is often phenomenal, rising above 60 metres, and the topography of the site means there is often plenty to see in the distance.
The name Admiralty comes from the centuries old admiralty-style anchor that sits in a cave which provides an entertaining (if a little narrow) swim-through and gives the reef a focal point. Otherwise this reef is characterised by healthy hills of coral interspersed with sandy channels. Visually it appears like a coral village and you can spend the whole dive touring around the sandy roads and lanes.
The slopes, pinnacles and mounds feature a lot of stony, leather and staghorn corals as well as crinoids in hues of yellow and black. Marine life includes schools of midnight snapper, red-tailed wrasses, goldstripe wrasses, lyretail hogfish and lyretail sandperch. More obvious Australian diving highlights include white tip and grey reef sharks, and the occasional passing eagle ray in the deeper sections.
Incredible visibility, pristine reefs, clean sandy channels and plenty of fish action, Admiralty is one of those Australia dive sites that you don't mind to visit several times over.
Around the Bend - Where you begin this dive depends on which of the 2 ways it is to be dived: either as a long deep drift or an easy exploration of the lagoon area.
On the drift you will be dropped beside a rising pinnacle that tops out at around 1 metre below the surface and you will sink done close to its base at around 15 metres deep. In optimal condititions a mild current will bring you gently over a highway of coral rubble which runs from 3 to 20m, dividing 2 sections of the reef. As you reach the other side of the highway, a bommie covered in soft corals will come into view. Atop this bommie is a line on to which you and some of your fellow divers may be instructed to hold and hang there in around 20 to 25 metres.
If you haven't already spotted them before getting to the line, you soon will: mantas, sometimes several, will come in and hover in the current enjoying all the facilities of what is a natural cleaning station. The rays seem to hang motionless as the little wrasses go to work picking parasites off the skin of the graceful beauties, some with a wing span of 3 to 4 metres. They tend to have white undersides with black topsides, dappled with various patches of white.
After several minutes marveling at these most alluring of creatures, you will probably then proceed to drift over a sandy channel where white tip reef sharks rest on the sea floor and a proliferation of soft corals heralds the entrance to a shallow lagoon. This lagoon is so beautiful and has such a number of things to investigate that it is considered a separate dive site in its own right.
In addition to the soft corals, the entrance is marked by a large boulder coral covered by Christmas tree worms. Inside, the lagoon is teeming with colour to the extent that 1 instructor declared it to be "like the gaming room of Crown Casino". Blue staghorn, swarms of damsels and anthias, all manner of Christmas tree worms and nudibranchs, all add to the riot of a colourful scenario around which an amazing array of butterflyfish flutter. You will spot varieties such as saddled, threadfin, pyramid and blackback butterflyfish. Plus look out for the 2 distinct types with differentially scaled proboscis that are prevalent when diving in Australia: the longnose butterfly fish and the ... very longnose butterflyfish.
Coral Canyons - Some dive site names offer little in the way of information about the site. The name Coral Canyons on the other hand, tells the story: large and long canyons dividing large coral outcrops.
The channels here are not fine sand but consist mainly of broken corals and rubble mostly lying between 30 and 40m, so you might begin your dive by trailing along the seabed. There are a number of different ways to dive this area which makes it several dive sites in one.
After the first few minutes, your dive will take the shape of passing up over and around various ridges that top out at anything between 20 and 10m. Around these reef-tops look out for red-breasted wrasses, arc-eye hawkfish, and clown triggerfish. If you head in a westerly direction you will ultimately come to the edge of the reef which drops to around 1,400m eventually becoming 3,000m. As you approach the edge you will probably be rising up over a ridge from where you can seemingly see forever. You may see a huge school of jacks near the reef edge, circling around and other large schools of yellow snapper and blacktail snapper.
Sharks are also present too and you are likely to spot several white tips resting on the canyon floors, plus grey reef sharks, particularly at the reef edge. With a gentle current you can cover a huge area here and it is a site that you can and may dive more than one time on your Australian dive trip.
False Entrance - False Entrance earns its name from appearing like the safe, navigable entrance to the lagoon, which in fact lies a few kms to the north. In strong current this can be a great drift dive and in slack water conditions, a normal reef dive with multiple bommies for investigation.
As you descend down through the water column you can start your dive at the reef edge that drops to a wall at a depth of around 30m. On this wall you can see a lot of gorgonian fans and sea whips. There are a number of sessile life forms reaching out into the channel to capture passing nutrients so their display is wide and the colours are impressive. It is worth checking out the blue for passing manta or eagle rays as well as white tips and grey reef sharks.
On this dive site there is normally excellent visibility, which makes the sight of the drop over the edge of the reef into the abyss all the more eerie. You will proceed up and around the bommies where there are plenty of sights to look out for. After a few minutes on each bommie there are little blue water swim-throughs to the next one.
You may spot scorpionfish, stonefish, banded pipefish, as well as arc-eye hawkfish standing on the hard corals. The bommies themselves are bedecked in hard and soft corals as well as coralline algae and funnelweed, giving this Australian seascape the look of a rainforest floor. Also look out for sailors eyeballs, sea squirts and feather stars, all adding to the colour and diversity of the scene.
When the currents are really running you can be dropped at a distance to one end of this reef system and drift dive through the whole area, stopping for moments of calm in the natural shelter afforded by the bommies. In these conditions look out for larger fish in the current such as barracuda and trevally.
North Horn - There are several ways to dive this site which is located at the northernmost tip of Osprey Reef, part of the Great Barrier Reef Marine Park. It can be done as a drift dive when current is present and a deep dive running down to 40m+. However it is as the site for a famous shark feed that North Horn is best known and will be remembered by you long after your Australia diving trip is over.
Often there is an orientation dive before the shark dive. On these, you will be taken down as far as perhaps 30 metres to where a bommie rises covered in soft corals, fans and whips. Many sites around Osprey Reef are known for healthy hard coral coverage so it is nice to see colourful soft corals represented here. Tracey's plaque, affixed to the reef, is in memory of a well-known local dive instructor.
North Horn Wall is practically a dive site in its own right with lots of ledges and gorgonian fans and the bigger pelagics in the blue. Eagle rays and manta rays often cruise around the vicinity and it has been known for divers to spot sailfish at this dive site, although more than a spoonful of luck is required for such a thrilling encounter. Just make sure that your camera batteries are fully charged and that the memory stick has plenty of room.
As you stride in here and begin to make your way down a line, you will be under no illusions as to why this site is used for a shark feed. You will likely see many of the main players before the action has begun.
You and your fellow divers will be seated in a natural coral rubble amphitheatre, where up to all 26 guests can sit in a semi-circle at around 12 metres deep. Between 10 and 15 metres from the viewing area, a drum of fish heads is released. Then the action begins and the sharks come in to feed. White tips, grey reef sharks and silky sharks (grey whalers) jostle for the spoils. Silvertips lurk in the background where even the occasional hammerhead shark can be seen.
You can expect a potato cod or two to be involved in the mix, rubbing shoulders with the sharks and a few dog-toothed tuna. Smaller Great Barrier Reef opportunists are on hand to sweep up the scraps with yellow-tailed fusiliers and red bass living of the smaller chunks dislodged by the sometimes violent feeding frenzy.
This dive is conducted under the strict guidelines of the Queensland government. The feed is sealed in a bin and the tender has to be removed before the feed is released, so the sharks do not associate flesh coming off the boat with a feeding frenzy. Only once the bin is gone and the sharks' attention is elsewhere will you be invited to move around.
The environmental management fee that you pay contributes to the creation of no-take zones and this area is one which, at the time of writing, is under consideration. Without doubt the images of shark diving in Australia at North Horn will live long in your memory.
How to Dive Osprey Reef
Due to its remoteness, access to the Osprey Reef is by Australia liveaboard only.
To cut down journey time to the reefs on shorter trips, some operators do also leave from, or return to Lizard Island, which is accessible by flight. The flight departs from Cairns and flies to Lizard Island over the reef, providing you a scenic trip with an overview of what you'll be diving on the Great Barrier Reef.
Liveaboard diving safaris to the Australia's Osprey Reef are very popular and fill up quickly. We recommend you book well in advance.
Got a question?
Have a look through our Frequently asked questions
Thanks to North Queensland's tropical climate, the northern Great Barrier Reef is a year round diving destination. The average water temperature never dips below 22°C in winter, with an average of a toasty 29°C during summer.
From June to November it's humpback whale season, with the coral spawning taking place around October / November, but a dizzying array of marine animals are on display all year round.
Visibility is great throughout the year, with exceptional visibility around September to November.
As the Australian summer is the wet season, the likelihood for rain increases around December to February, with showers usually confined to mornings and late afternoons. Winds are also changeable during this monsoon period and may affect itineraries. During the winter months, the dry season, rainfall is pretty low.
Surface conditions through the year are calm, with June to August experiencing moderate conditions. Monsoon months may bring less settled surface conditions.
Good for: Visibility, underwater photography, large animals, walls, reef life and health
Not so good for: Small animals, wreck dives
Depth: 5 - >40m
Visibility: 10 - 60m
Surface conditions: Generally calm but can be choppy
Water temperature: 25 - 30°C
Experience level: Intermediate
Number of dive sites: ~15
Distance: ~350 km north of Cairns
Access: Australian Liveaboards
Recommended length of stay: 1 week
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