Michael McFadyen's Scuba Diving - Northern Wall - Raine Island, Queensland
Great Detached Reef is located at the northern end of the Great Barrier Reef off Queensland, Australia. It is about 125 nautical miles (230 kilometres) from Thursday Island in the Cape York area (the pointy tip of Australia) and 75 nm (140 kilometres) from Lockhart River. The is 45 nm (85 kilometres) east-north-east from closest point of the Australian mainland, Cape Grenville. It is just over 4 nm south of Raine Island, the largest green turtle nursery in the world.
|A chart showing the location of Great Detached Reef (bottom right)|
and Thursday Island (top left)
|Raine Island - North Wall is under the word island|
Northern end of Great Detached Reef below it
There are only a couple of boats that travel to this area, one being Kalinda which routinely does full boat charters there in November and December. Another boat does some trips there and one more might go there once or twice a year.
Kelly and I travelled here in November 2016 on Kalinda with fellow members of St George Scuba Club when we chartered the whole boat. We flew into Horn Island (next to Thursday) and started our trip from there.
As mentioned, Raine Island is a short distance north of the Great Detached Reef which is where we did most of our diving on this trip. Raine Island "is the largest and most important green sea turtle nesting area in the world, with up to 18,000 females nesting on the small coral sand cay in one season. The turtle population can vary from a figure of less than 1,000 to more than 10,000". It is also "the longest known marine turtle rookery anywhere in the world" (quotes from Wikipedia). Despite what we were told of over 10,000 turtles a night laying eggs, it still is an extremely important location.
Northern Wall is located on the reef to the north-east of Raine Island. Its location is approximately GPS S11Âș 35.3760' E143Âș 02.7887'. The island is surrounded by a reef which is quite a way from the island on this side. The top of the reef is a metre or so and it slopes gradually to about five metres before dropping quite steeply to well over 30 metres.
The boat cannot anchor here as it is too deep, so it is done as a drift dive. The main aim of the dive is to not necessarily look for green turtles, as they are very common on the Great Detached Reef, but to see tiger sharks. The tiger sharks come here to feed on injured, dead or tired turtles.
|Kelly on the wall||A green turtle resting in one of the "turtle beds"|
The wall here runs from the north-west to the south-east. Once we were in the water, we dropped to 20 metres and headed south-east with the very slight current. The wall here drops very steeply from 5 to over 60 metres.
The one thing you soon notice about this wall is that there are thousands of "turtle beds" in the wall. What I mean by this is that there are small areas just large enough for one green turtle to lay on the bottom. They sort of look like bunk beds in the side of the wall. While most were empty, quite a few had turtles in them.
As we drift along, we see plenty of turtles, both swimming in the open water as well as resting in their beds. We certainly see more here than at our previous dive at Eastern Apex. We also see one leopard shark resting on the wall, one epaulette shark and a few reef sharks. There are many schools of of unicornfish, surgeonfish and parrotfish and a few titan triggerfish.
|A green turtle swimming off the reef||A resting leopard shark|
After 35 minutes we are in five to seven metres, and spend the next 20 minutes looking at this shallow reef as we head along. There are some anemones and clownfish in this area. When we ascend, we swim out away from the wall and are picked up by Kalinda.
Despite (probably) not seeing any tiger sharks here, we did see one inside the Great Detached Reef, but only from above the water. Even so, that was pretty exciting.
We dived here in November, the water temperature was about 28ÂșC, visibility about 25 metres. A really nice dive site.