Michael McFadyen's Scuba Diving Web Site
Home Contact Me Sydney Reef Dive Sites Sydney Shipwrecks NSW Dive Sites Australian Dive Sites Overseas Dive Sites Dive Accidents and Incidents My Yachting Adventures 4WD Trips Weather Search 29 May 2024 11:17

About Me
My Diving
Web Links - Dive Clubs
St George Scuba Club
Some of my Best Photos
Contact Me

Dive Sites
Sydney Reef Dive Sites
Sydney Shipwrecks
Sydney Dive Visibility, Swell and Temps
Kelly Talking on ABC Sydney about Shipwrecks
NSW Dive Sites
Sydney Shipwreck Summary
NSW Shipwreck GPS/Marks
Australian Dive Sites
Overseas Dive Sites
Aircraft I have Dived
Old Bottles
Free Shipwreck Books

Dive Related Equipment
Shearwater Predator and Heinrichs Weikamp OSTC 2N
Uwatec Aladin Dive Computers
Apollo AV1 Underwater Scooter
Bauer Compressor
DIY Oxygen Stick - Nitrox
GoPro HD Hero Video Camera
My Camera Setup
Purchase of New Dive Boat
My Dive Boat - Mak Cat
My Old Dive Boat - Le Scat
My Dive Gear
GPS and Diving
Make Your Own Car Tank Rack

Marine Life
Rarer Sydney Marine Life
Bare Island Pygmy Pipe Horses
Bare Island Sea Horses
Bare Island Nudibranchs
Bare Island Marine Life
Encounter with Southern Right Whale and Calf

Other Dive Info
How Weather Affects Diving in Sydney
Visibility and Wave Averages in Sydney
Waves and Diving
Diving Weather and Sea Conditions
Tide Tables
Dive Accidents and Incidents
Dive Book Reviews
Site Map
Noel Hitchins 1951-2005
Lloyd Bridges - Mike Nelson in Sea Hunt
My Yachting Adventures
Below is a list of links to the main pages about my yacht, Catlypso and My Yachting Adventures:
  • Purchase of Catlypso
  • Details about Catlypso
  • Cleaning/Repairing Catlypso
  • My Yachting Adventures.
  • Login


    Forgotten your password?
    Request a new one here.
    Michael's 4WD Trips
    Click here for a list of my Four Wheel Drive and Camping Trips.
    Home Brewing
    Click here for an article about Home Brewing.
    Sydney Dive Site Hints
    "Inscription Point is a great place to find sea dragons"
    Coral Castles - Osprey Reef
    Osprey Reef
    A chart of Osprey Reef
    Coral Castles is the top black dot
    Osprey Reef is located approximately 130 kilometres off the Great Barrier Reef in the Coral Sea. It is about 200 kilometres from the mainland. The reef itself basically runs from north-west to south-east and is about 30 kilometres long and 10 kilometres wide. There is a single decent entrance to the only lagoon (which is about 25 to 27 metres deep for the most part) that is located about two thirds of the way from the southern point to the northern point. Boats steam to Osprey from the GBR overnight, with most boats taking about 10 to 12 hours depending on the conditions and where you are leaving the main reef.

    This dive site is located about half way between the northern most point and western most point of Osprey Reef. The reef loops in a concave shape from these two points and the dive site is approximately the eastern most point of this section of the reef. The mooring is located on a bommie at about 15 metres. The GPS Reading for the mooring is S13° 50' 56.5" E146° 33' 50.6" using WGS84 as datum. It is approximately 315 kilometres from Port Douglas.

    The reef here is composed not of one complete section of reef, but many huge bommies. These give the name to the dive site as some of them do look like the traditional "castle". In between the "castles" there are gullies and canyons. Some are narrow and form tunnels and others are quite wide and deep.

    When you enter the water, drop to the reef side and head to the south. There is unlikely to be a current, but if there is, it will be coming from this direction. As you head south, go to about 30 to 32 metres. There are some large (proper) caves here and if you go inside, you will get some nice photos if your buddy stays outside in front of the cave's entrance. See the ones below.

    You can go a fair way before you need to turn around. Come up a bit as you go, staying out of decompression. You will see more caves and tunnels and lots of canyons between the bommies. You can go up some of the canyons and at the end of a couple you will find a large sand area. This is worth exploring. Come back to the main reef via one of the canyons. you could also go over the reef at the side of the sand area (if there is no suitable canyon) and then come back to the main reef.

    Once you decide to turn around, come back a fair bit shallower (say 20 metres). This will enable you to explore more of the cnayons.

    Coral CastlesCoral Castles
    Kelly swims along the wall at Coral CastlesOne of the many caves at Coral Castles

    Once back at the mooring area, go around each of the main bommies. The one to the north of the mooring has a tunnel from north to south. This is easy to swim through and provides good photo opportunities. There are said to be more tunnels and swim-throughs in the base of other bommies, especially the one to the north-east, but I could not find any of them.

    The sand in between some of the bommies have garden eels and there are also some white-tipped reef sharks here as well.

    Coral CastlesCoral Castles
    Kelly swims past a nice coral outcrop along the wallKelly enters another of the caves at Coral Castles

    When you need to leave the bottom, come up around a bommie, examing all the nooks and crannies. There are some very nice soft and hard corals on these bommies and lots of fishlife.

    Again, the visibility is excellent here, at least 40 metres. Water temperature was about 26C in November.

    This is also an excellent night dive. A similar dive to the one described above should be done but do not go past about 20 to 22 metres. You can see flashlight fish in caves, overhangs and canyons. You can also see many firefish, one or two sleeping turtles and lots of shrimp and small crabs. One of the best night dives I have ever done.

    Coral CastlesCoral Castles
    The Undersea Explorer from about 35 metresA firefish seen on a night dive

    Click here to return to the Osprey Reef article page.

    Copyright © Michael McFadyen 1990 to 2024
    Non-commercial use of an article or photograph is permitted with appropriate URL reference to this site.
    Dive shops, dive operators, publications and government departments cannot use anything without first seeking and receiving approval from Michael McFadyen.
    This web site has been wholly thought up, designed, constructed and funded for almost 30 years by Michael McFadyen without any help from the Australian Dive Industry.
    Website created 1996!