Swains and Pompey Reefs

Swain Reefs

The Swains Reef complex is 100km to 250km (62 miles to 155 miles) from the coast and has over 270 reefs, with more than 25 with cays. The reefs range in size from a few hundred metres across to over 20km (12 miles) in length. The reefs are rich with life and the cays are important as protected sea bird rookeries and resting areas. Most of it is unexplored relatively for diving with high marine life biodiversity. There is a variety of coral structures, especially on the more sheltered north and eastern ends of the reefs. They represent the most eastern development of the Great Barrier Reef.

Good walls, excellent reef edges, gut-ters, drop-offs, tunnels, swim-throughs, ledges, terraces, caves, overhangs and large coral heads occur throughout the area. Shallow lagoon reeftops and sandy floors host large staghorn thickets. Most of the area is less than 30m (98ft) deep between the reefs, with less deep diving than the Coral Sea sites to the north. Visibility can be reduced during rough weather and big tides.

Many species of shells can be seen, especially at night. Sea snakes are common at some reefs and sharks, turtles and rays can be seen throughout the area. Much of it is in reserved area with commercial trawling still allowed in some western areas. Fish stocks in some parts of the Swain Reefs have been depleted of larger fish of some species such as trout, cod and sweetlip. It is usual to see larger fish like trout, cod and whitetip reef sharks in the gutters. Small angelfish, butterflyfish, damsels, surgeonfish wrasse and parrotfish are common. Feather stars sit up on the fan corals catching passing food. This site is good for wide-angle photography on most days but is always a great macro area as well. Numerous varied sites provide for a great snorkel or dive on this reef.

Much of the area is unexplored, each dive boat takes divers to their favoured spots, usually associated with a good anchorage. There are many anchorage sites so even if there are a few boats out, it is unlikely you will cover many sites, as the area is so large. Depending on which harbour you started from and how long you have, you will probably cover either the northern or southern section. Usually there is no set itinerary, your trip will be determined by weather and the interests of the rest of the group. Trips from Gladstone and further south rarely get north of Herald’s Prong No.2 before running low on time and fuel.

In the 1990s the Swain and Pompey Reefs were the most visited liveaboard destinations on the reef. Direct flights to Cairns saw tourist numbers soar and operators headed north following the money. At the moment there is one cruise operator based at Gladstone, and one out of 1770, offering 7 and 10 day charters. Charter operations are typically conducted every week for nine months of the year outside of the summer months. While their primary charters are fishing-based, they also conduct dive and snorkel charters.


Hixon Cay


This cay provides a sheltered anchorage and shallows that are suitable for diving or snorkeling on colourful coral gardens. There are lots of coral heads near the main reef with small gutters and overhangs. The coral is mainly staghorn and plate forms. The gardens are patrolled by fish and a few reef sharks in deeper sections. On the southern side, a deep wall offers pelagic fish including reef sharks and mackerel. Jobfish and rainbow runners can also be seen. The current affected walls are covered in sea whips, gorgonia and soft corals.


Taiwan Reef


The lagoon offers lots of school fish and plenty of colourful coral.


Blue Line Lagoon

This circular reef offers a drop off with plenty of pelagic fish, reef shark and groupers. This area is at the northern point of most southern based charters and divers will notice sea snakes on dives and coral formations of increasing colour and variety. This site lies on the outer Swains, close to the open sea.


Middle Cay


This site offers a drop off covered in huge yellow and red gorgonia. Clouds of smaller fish inhabit the hard and soft corals on the walls. The drop off wall also has plenty of crevices and overhangs that house a wide variety of fish


Gannet Cay


Apart from a huge seabird colony, this site offers coral pinnacles off the southern side bursting with fish including sharks and manta rays. The pinnacles can be current-affected. At dusk huge flocks of seabirds will return to roost on the cay, a very impressive sight.


Sandshoe Reef


This reef offers extensive coral gardens packed with fish and exotic marine invertebrates including flatworms, nudibranchs and sea stars. The reef-dwelling fish are also numerous and diverse including, anemone fish, damsels, filefish and triggerfish.


Sinker Reef


Deep gutters in the coral gardens make it into a maze of features. These features are home to reef dwelling fish including batfish, sea snakes, grouper, lionfish, butterflyfish and barracuda.


Hook Reef


This is another complex of coral garden offering excellent fish and invertebrate life.


Horseshoe Reef


This is considered one of the most diverse and interesting reefs on the Swains. This reef offers a large lagoon with many dive sites and a safe overnight anchorage. The SE reef top is marked by the wreck of an old Taiwanese fishing boat, now high and dry. On the southern side near the wreck, there is a deep wall with many ledges packed with marine life. There is an array of filter feeding animals as well as turtles, pelagic fish and reef sharks. On the southern flank of the reef, there is an opening in to the lagoon that offers good drift diving. These walls are exposed to the prevailing winter weather. The NW side of the lagoon offers sheltered diving in shallower coral gardens.


Snake Reef


This site offers very deep walls for the experienced diver packed with colourful growths along the wall and swept by schools of pelagic fish.


Central Reef


This reef offers a variety of mostly shallower diving on coral gardens. The area is good for macro photography with plenty of smaller creatures to find on reef faces, and plenty of smaller and unusual reef fish.


Mystery Cay


The southern side of this reef has extensive coral gardens with smaller pinnacles. These coral heads are visited by mantas in the winter, to use nearby cleaning station. There are also plenty of other fish and invertebrates to see and photograph.


Lavers Cay

There are many ledges and gutters on the northern side with good corals and fish life. One of the attractions are huge grouper up to 2 metres in length.


East Cay 


Boat operators like this reef due to the easy-access anchorage and small sand cay. Complex bommies and gutters provide great swim-throughs, especially on the north and eastern ends of the reef with sandy floored areas in between. In the sheltered areas there are staghorn thickets and small coral patches. The bommies reach from sand at 20-25m to the surface. It is usual to see larger fish like trout, cod, whitetip reef sharks, angelfish, butterflyfish, damsels, surgeonfish, wrasse and parrotfish. Sea snakes are common. At night there are lots of small invertebrates including shells on the sand.



This reef system of about 150 reefs lies between the Swain Reefs and Whitsundays. Most have no names and are recognised only by their numbers on the Marine Park Zoning Plan maps. The Pompey Complex is about 200km (124 miles) north-to-south, 90km (56 miles) west-to-east and up to 185km (115 miles) from the mainland coast.

The tide rise and fall at the Pompeys is 7m (22ft) inside and 4m (13ft) outside, the largest on the east coast of Australia. It is usual to see tide runs in excess of 15km/h (9mph), which causes whirl-pools and rising water that is 10cm to 20cm (4in to 8in) higher than the adjacent reef. This makes the marine life rich and hardy, able to withstand intense water speeds. This is the most southern point to find the giant clam.  The currents ensure great populations of pelagic fish and filter-feeding invertebrates. The tides make diving more complicated and it’s an area for experienced divers in many locations. However, the area has a variety of terrain but most of the area is less than 30 metres in depth near the reefs. The reefs offer good shelter and there are also many safe and easy dive spots for newer divers. The visibility is usually excellent, 30 metres or more. Visibility can be reduced during rough weather and big tides.

In the lagoons and lagoon entrance mouths, rich staghorn beds and coral gardens, abraded coralline algal surfaces and many grazing fish. Sharks, barracuda, rays and mackerel circle in the eddies. On the lagoon floor, many shells and feeding sea cucumbers and goatfish can be seen.

On the lagoon reef edge there is rich marine life, especially in the small overhangs and caves. You’ll see worms, crabs, crayfish, shells, soft and hard corals and sea cucumbers. Coral cover on some reefs in the Pompey sector is variable and still recovering from the impacts of Severe Tropical Cyclone Hamish, low level coral bleaching and a number of prior disturbance events.

Between the reefs are channels up to 90m deep and 200m across. They are u-shaped and were probably formed during the last ice age. Their sides are vertical walls that fall to a smooth limestone floor. They are tide-affected and visited by large schools of fish.  The mid-reef wall has smaller life adapted to intense water flows. Hard corals, soft corals, sponges, coralline algae and many small fish abound. Life inside the caves and overhangs tend to be larger.

At least three blue holes occur in the complex. These are usually old caves that formed during the last ice age and collapsed as the waters rose. They are very photogenic but fish life is limited, but you’ll see stripeys, sweetlip, trout, damsels, butterflyfish, wrasse, parrot-fish and angelfish.


The New Blue Hole


The most recently located blue hole is 100 metres in diameter this has sheer walls going down as far as 90m if you have a death wish and don’t control the decscent. It is lined with small corals and some fish have got over the reef top at high tide and swim around the hole. This is a dive for experienced divers.


Cockatoo Reef Blue Hole


This is one suitable for less experienced divers and is located inside a shallow 10m lagoon. It’s exposed at low water as a dark blue circle 200 M wide. The wall stops at 7m then slopes inward forming a pool with smooth sand/sediment sides to 30m. There are rich staghorn corals on the wall only close to the surface. All coral stops at about 15m as it becomes buried in sediment. Fish life is limited.