A chart showing the location of Great Detached Reef (bottom right) and Thursday Island (top left)	Great Detached Reef - Woodies is located on the western side of Wood Reef and is marked

Great Detached Reef is a reversed C shaped reef made up of a number of separate sections. It is located a little off what is the main outside section of the Great Barrier Reef, although here that reef is merely a series of small bommies or reefs. Great Detached Reef is 11.5 nm from north to south and 8.8 nm east to west. The west (open) side of the reef has a series of bommies and small reefs along a large part of its length.

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.

Woodies is located on the western side of Wood Reef which is about 0.7 nautical miles south-west of the south-western corner of Great Detached Reef. Wood Reef is a triangular shaped reef about 2.5 by 1.5 nautical miles. The longest length runs north-west to south-east. Woodies' location is GPS S11º 47' 27.3" E143º 57' 28.1". The site is just north of the entrance into the Wood Reef Lagoon (which is not as shown on the chart above).

The site is a long finger or reef that runs out about 150 metres from the main reef at a depth of about five metres. It drops off very steeply either side and at the end to over 100 metres. The reef has a tunnel through it almost at the end. This is at 20 metres and runs for about 20 metres through the reef. It is five metres wide and a few metres high.

Kelly on the reef wall	Kelly exits the tunnel

We anchored in about 20 metres on the southern side of the point in towards the main reef. Once in the water we dropped to the bottom as soon as we could see it. Heading west, we swam along at about 25 metres looking for the tunnel. We ended up being a bit too deep. We were told that the tunnel was in a sort of landslide area, two from the boat. It turns out it was more like the fourth one, but we easily found it.

This whole section of reef is very spectacular, the shear vertical wall has lots of gorgonias and sea whips. The tunnel is really interesting and you can get some excellent photos looking out and through the tunnel.

Another section of the wall	A grey reef shark

Once you exit the tunnel, turn left and start dropping. We went to 32 metres as the best gorgonias and sea whips are down deeper. We also saw a large grey whaler and a large silver-tipped reef shark out here. If the current is running (it was not for us), then this point would be an excellent place to see sharks.

We headed back to the east, this time on the northern side of the point. There are plenty more gorgonias and sea whips along the way. We gradually came back up to 20 metres and maintained this depth all the rest of the way back. There are two places where you can cross over back to the southern side. One is about two thirds of the way back and the other is right on the main reef. We took this latter one.

Three long-nose filefish	A clown triggerfish

The channel back to the south side is about three metres deep. We saw a few more small sharks here. Once across, we came back to near the boat and spent the rest of the time in five metres. There is some excellent coral here, with plenty of anemones, clownfish and all the usual species.

We also saw lots of trevally, surgeonfish, unicornfish and more in the deeper water on this dive.

We dived here in November, the water temperature was about 28ºC, visibility was about 30 metres. An excellent dive site.