A guide for divers and snorkelers
Given the huge size of the Great Barrier Reef, it is no surprise that there is a rich of diversity. Scientists at the Marine Park Authority have noted 30 distinct reef bioregions. There are hundreds, make that thousands, of dive sites. With this guide we hope to simplify the issue and help you select the area you wish to explore.
Dive Trips leaving the Cairns/Port Douglas Region visit four fairly distinct areas, each of which offers different opportunities. Use this handy guide to help select which reef region you explore on your visit to Australia. Be sure to check out the weekly reef reports to get a better idea of what diving in these regions can be like at different times of the year.
There are four main reef regions in this section of the Great Barrier Reef:
Cairns/Port Douglas Reefs - For divers and snorkelers, 1/2-day to 4-day trips, year-round.
Northern Ribbon Reefs - For divers and adventurous snorkelers 2 to 5-day trips, year-round
Coral Sea Reefs - For divers, 4- to 7-day trips, year-round.
Far Northern Reefs - For divers, 7- to 10-day trips, October-December only.
Cairns/Port Douglas Reefs
These Reefs lie offshore of Cairns and Port Douglas, and are within range of the one-day dive trips that leave these towns.
There are an enormous number of reefs here, and an equal variety of reef trip operators, with the combination resulting in a great variety of diving and snorkeling opportunities. There are trips just for snorkelers, trips just for divers, and still other trips that visit islands or large pontoon decks moored on the reefs, a perfect place for families with younger and older folks coming along. There are also many liveaboard boats operating in the area, offering 1-4 day trips, and a chance to experience the thrill of a night dive.
The trip out to the reef from this area takes between one and three hours, depending on the speed of the boat, and which reef you are visiting.
The diving and snorkeling in this region is equally varied. The reefs here are is known for having lots of hard corals, a variety of colorful reef fish, and for the wonderful surprise appearances of sea turtles, humpback whales, dolphins, and other remarkable creatures.
You may hear the term "Outer Barrier Reef" being used by trip operators. Scientists characterize this bioregion as "Outer Shelf Reefs." Both terms are used to distinguish reefs located on the outer, western edge of the reef system from the sand cays and reefs that lie closer to Cairns. Outer shelf reefs are more open to the Coral Sea, and less influenced by coastal conditions, especially rainfall.
Lying closer to shore are the Coastal Northern Reefs and Exposed Mid-Shelf Reefs. Good examples of these reefs are those around Green Island, Fitzroy Island, and the Frankland Islands. Getting to these locations takes less time, but they are more readily impacted by silt running off the land after storms during the wet season (Feb.-Apr.) and stirred up by Southeast trade winds during the windy months. However, the diving and snorkeling here on calm days during the dry season can be very good.
For an extensive listing of reef trips in this region use our handy reef trip search page and let the computer search through an archive of over 100 trips to find the trips that suit you best.
Northern Ribbon Reefs
The Northern or Ribbon Reefs lie 40-60 miles north of Cairns and Port Douglas.
This long chain of narrow reefs extends all the way up to Lizard Island, and offers some outstanding diving and snorkeling. The visibility on these reefs is consistently better than the reefs closer to Port Douglas and Cairns. The most well-known dive site is Cod Hole, famous for its resident population of large (up to 350 pounds!) potato cod, which are joined by groups of large Maori wrasse and other fish that have become accustomed to the presence of divers.
These reefs offer a range of great diving sites, skippers have a lot of choices to of dive sites, enabling them to choose the best diving available based on the tides, winds, and weather. Due to their greater isolation from large rivers, agriculture, and coastal development, the visibility on these reefs can 3-5 meters better than off of Cairns and Port Douglas.
The northern reefs are out of the range of one-day reef trips; most trips out this way range from 2-5 days. Some trips, in an effort to minimize boat travel, have their trips arranged so clients travel one leg of the trip as a low-altitude flight to or from Lizard Island.
To see a full listing of dive trips that visit the Northern Ribbon Reefs use our handy reef trip search page.
Coral Sea Reefs
The Coral Sea lies outside of the Great Barrier Reef, to the North and East of Cairns. There are a few small coral atolls and surrounding reefs set in the Coral Sea some 60-100 miles offshore. These reefs, (Holmes, Osprey, Horn, and Bouganiville Reefs) are visited by just a few dive boats, and offer some amazing diving opportunities, well worth the long overnight trip that is required to reach there.
Being so far away from shore, the visibility at these reefs is consistently amazing. Typically, visability is between 25 and 35 meters. During June, July and August it can be as high as 60 meters.
These reefs are known for their populations of large pelagic fish. If you like big fish, this area will be one of your favorites. Sharks are common in the area, especially reef sharks and silver tips, with hammerheads and other shark species making appearances timed with their annual migration patterns. Other pelagics are also abundant, including dogtooth and big-eye tuna, mackerel, potato cod and various species of trevally. At Holmes and Osprey Reef, dive operators have been holding shark-feed dives for a number of years, so you will see these pelagics at a very close range. (To minimize your risk, be sure to follow the instructions of the operator on these dives.)
Dive trips to these locations take from three to seven days. Many of these trips also visit the northern ribbon reefs, another outstanding dive region,
To see a full listing of dive trips that visit the Coral Sea Reefs use our comprehensive reef trip search page. (Tip: search for trips that are 4 days or longer.)
Far Northern Reefs
The Far Northern Reefs are aptly named; they make up the northernmost portion of the Great Barrier Reef, over 200 miles from Cairns and Port Douglas. (On our online map these are the reefs that lie north of Lizard Island, continuing all the way up to the tip of Australia.) This is a huge region with over 600 reefs, and spectacular diving, but due to the remote location, sees very little diving. Scientists have noted four distinct reef bioregions here, some known for their rich and distinct diversity of bottom life, others for their diverse corals, fish life, and abundant sea turtles.
The diving here is largely exploratory, with just a few 7-10 day trips offered during the months of November and December, when dive conditions are at their absolute best. This time of year is when much of the reproduction occurs on the reef, so along with a huge diversity of life, there is lots of interesting animal behavior that is not seen at other times of the year. The diving is rich and varied.
Due to the distance required to travel here many dive trips will have one leg of the trip be a flight to Lizard Island or Lockhart River. This saves you time, and gives you a chance to see this beautiful coastline from the air. Dive trips here are popular, and you will need to plan well ahead to assure yourself of a place on one.
To see the full listing of trips to the Far Northern Reefs use our handy reef trip search page, and search for trips that are 7-days or longer.