I recently joined Nimrod Explorer on an 11 day trip to the Far Northern Reefs of the Great Barrier Reef. This is an area that I have always wanted to dive, as not only does it offer the greatest biodiversity to be found on the Great Barrier Reef, but much of the area is still unexplored. During our trip we had the opportunity to do many exploratory dives in what is the last frontier of the Great Barrier Reef.
Nimrod Explorer is one of the only charter boats offering scheduled trip to this region, which is 600km north of Cairns. Only four trips are organised each year, in October and November when the weather is most stable. The first and last trips explore the reefs north of the Ribbon Reefs on the way up and again back down. The other two trips explore the heart of the Far Northern Reefs, and this was one of the trips I was on.
Arriving in Cairns I met my fellow divers at the offices of Nimrod Explorer. Les, Ken and Rosemary were all from the USA, Steve was another American based in Japan and Mandy was the only Australian, apart from me. Six passengers on a vessel surveyed for 18. Another large group from the USA had cancelled at the last minute, their loss, but our gain!
It was then off to the airport for our flight of 600km up to the Lockhart River to met up with the boat. The flight was very spectacular, over rainforests, rivers and dozens of reefs. Two hours later we landed at the Lockhart River airstrip. We then loaded into a 4WD for the 40km trip to Portland Roads.
Lockhart River and Portland Roads area were a major military base during World War II. Numerous airstrips and 40,000 US troops were stationed here. The remnants of this large military presence is still there if you have time to search around in the bush, however we didn’t have the time as we had a boat to catch.
Transferring to Nimrod Explorer we met the crew for our trip. Mark was skipper, Paul the engineer, Demi and Dennis the Divemasters, Amy our hostess and the most important of all was Molly our cook, or I should say chef.
Nimrod Explorer is a 22m long catamaran that is very spacious. She has a large dive deck, lounge room and shaded upper deck. Passengers are accommodated in six comfortable cabins, each of which have their own bathroom and are air-conditioned. With our gear stowed, the anchor was lifted and we headed out to the reef.
Within three hours we had reached our first dive site, a checkout dive at Lagoon Reef. The visibility was a little cloudy at only 15m, as it was late in the afternoon (the visibility averaged 25m to 30m throughout most of the trip). However the water temperature was a lovely 28 degrees and the seas were calm. The coral at this site was very rich and there were numerous reef fish around; including coral trout, surgeonfish, unicornfish, Maori wrasse and even a few white tip reef sharks.
We then departed for an overnight cruise up to Raine Island. Dinner was served on the way, as the conditions were very calm. This was just the first of the culinary feasts that Molly produced each day in the galley. The food on Nimrod Explorer is varied, wonderful and never ending, all you seem to do is dive and eat.
We arrived at Raine Island at dawn. This small coral cay is the most important green turtle nesting site in the world, and the diving isn’t too bad either. We did several dives on sheer walls adorned with brilliant corals and patrolled by pelagic species. However since this article is about exploratory diving I won’t go into details, but if you are interested see my more extensive article on the Far Northern Reefs in future issue of Sportdiving.
The next day we dived a number of established sites on the northern and western sides of Great Detached Reef. Walls, caves and magical pinnacles packed with marine life. We then headed over to Semi Detached Reef for our first exploratory dive.
Late in the afternoon Mark positioned the boat at an interesting cove in the reef wall. A dusk dive was on offer, and I was almost going to give it a miss, having already done four dives that day. However when Mark jokingly put up the name of the dive site as Nigel’s Nook on the whiteboard, I thought I should take a look.
The site was a wonderful drop-off, the wall decorated with colourful gorgonians, sea whips and soft corals. Cutting into the wall were ledges, caves and many nooks. Steve, Les and I buddied up to explore the wall and were only in the water for a few minutes when a 2m long silvertip shark greeted us. For the next few minutes the silvertip cruised around us, getting closer and closer. Steve started to flash his torch at it, which brought it in even closer, and with its pectoral fins down. This prompted Steve to turn off his torch. The shark then reacted by swimming off into the blue.
We also saw a couple of white tip reef sharks and grey reef sharks during the dive before it got dark. I was concentrating on macro subjects, finding lionfish, sea stars, nudibranchs, clingfish, shrimps, crabs and many other invertebrate species. We explored a number of small caves, and then found quite a large one that cut deep into the reef wall. This cave went in around 10m and then branched out into a number of dead ends, except for one, which hooked around in a U shape to exit on another part of the wall. It ended up being a brilliant dive, so the next morning we did a drift dive to explore more of the site.
Drifting along the wall we saw Maori wrasse, surgeonfish, unicornfish, fusiliers, grey reef sharks and white tip reef sharks. Towards the end of the dive we spotted a 2m long Queensland groper. I followed the groper until it disappeared into the U shaped cave we had discovered the previous evening.
Heading back to Great Detached Reef, Mark took Nimrod Explorer for a closer look at the lagoon entrance at the southern end of the reef. On the way we ran over a very interesting pinnacle that rose from 50m to 20m on the sounder, but with a ripping current it was decided to explore the lagoon entrance.
With a fast flowing current, it looked as if we could do an exciting drift dive from the lagoon, along the reef wall and into a sheltered cove to be picked up. We quickly geared up and with a live boat running jumped into the water and quickly descended. The visibility inside the lagoon was a little cloudy, but once into the lagoon channel it opened up to 30m.
The walls of the reef tumbled do
wn to 35m, with the channel swept bare by the daily currents. Within
minutes of entering the channel the current died, no drift, however it meant
that we could explore the reef wall and the channel a bit more thoroughly.
Sprouting from the channel floor were many long sea whips, and between then were
countless garden eels swaying back and forth. The reef wall was highly decorated
with gorgonians, sea whips, soft corals and black corals. Pelagic fish
constantly cruised by; jobfish, trevally, dog tooth tuna and rainbow runners to
name a few.Also spotted were white tip reef sharks, turtles and a family of Maori wrasse. It was quite amazing how many Maori wrasse we saw on this trip, every site we dived seemed to have a resident family. At the end of the dive we ended up in a lovely coral garden with a multitude of reef fish. Dennis was also lucky enough to see a school of pygmy devil rays.
We then returned to Raine Island for a few more dives. The next morning found us in Wreck Bay doing an exploratory dive on an unnamed reef that the crew call Sushi Reef. It was to be another drift dive, but with the currents being so unpredictable in this area, the direction of the drift was determined only after we got in the water. This was another superb dive along a reef wall and channel. More impressive corals, grey reef sharks, barramundi cod and another family of Maori wrasse. The dive kept getting better and better, with more fish and sharks. At the end of the dive we found ourselves hanging over a drop-off and surrounded by a school of spawning parrotfish and three small grey reef sharks.
The rest of the day was spent diving Mantis Reef at a wonderful dive site called Black Rocks. The next day we did more dives at Mantis Reef in very glassy conditions; no wind and no swell. With the glassy conditions continuing the following day, Mark decided to head out to Northern Small Detached Reef for some exploratory diving. This tiny reef, some 10km off the main reef, has rarely been visited. Nimrod Explorer had never had the right conditions to visit it in any of her previous trips to the region.
Once a mooring line was attached to the reef we were all eager to explore. Sheer walls disappearing into the depths greeted us, and dropping down the wall we found it riddled with small ledges and caves. Decorating the wall were large gorgonians, spiky soft corals, sea whips, sponges and some very colourful black corals. The visibility was a little disappointing at only 15m, reduced by a cloudy oceanic current. Moving along the wall we soon saw white tip reef sharks, grey reef sharks and schools of surgeonfish, rainbow runners, fusiliers and unicornfish. The highlight for me was seeing a school of oceanic triggerfish. Although they never came in close enough to photograph, the school of several hundred oceanic triggerfish constantly swam past us, propelled by waving their large dorsal and anal fins. The next two dives were very similar around other parts of this rarely visited reef.
Two of the best exploratory dives of the trip were done the next day at Lagoon Reef. In the afternoon Mark was looking for a new dive site and noticed an interesting sandy cove in the reef. Dropping the anchor into the sand we geared up to take a look. Here we found a reef wall dropping to 35m. Masses of fish were patrolling the wall; trevally, mackerel, fusiliers, surgeonfish, goatfish and sweetlips. On the sand patch were numerous coral bommies. Here we saw turtles, Maori wrasse, barramundi cod, coral trout, giant clams, white tip reef sharks, cuttlefish and a colony of garden eels. With such a wealth of marine life Mark named the site Nature’s Way.
We then dived the site at night, seeing two jumbo sized painted crayfish and an assortment of fish, either sleeping or hunting. The invertebrate species was amazing; nudibranchs, flatworms, shrimps, crabs, sea stars, brittle stars, feather stars and a wide variety of molluscs. I also found a bizarre sand coloured crab that was barely visible on the sand and was entranced by a wickerwork sole that swam just like a flatworm. At the end of the dive we had a lot of fun on the deco stop being circled by all the baitfish and planktonic life that had been attracted to the deck lights.
The following day we headed out to Southern Small Detached Reef diving some of the crew’s favourite sites. Wonderful wall diving, but again the visibility was a little low from the dirty oceanic current, a far cry from the usual 40m visibility experienced at the site.
On our final day the wind picked up, blowing 30 knots from the southeast. Mark decided to head to the northern end of Log Reef for our last exploratory dive. We jumped in for another drift dive along the reef wall and were pleasantly surprised to find the visibility was 30m. There was plenty of pelagic action; barracuda, trevally, mackerel and rainbow runners. We also saw Maori wrasse, turtles, white tip reef sharks, schools of fusiliers and a wide variety of reef fish. The wall was again covered in lovely corals.
Towards the end of the dive we found a sandy bay dotted with bommies and home to garden eels. Suddenly a monstrous 2.5m long Queensland groper loomed up from behind a bommie and came in straight towards us. It then circled another bommie and took one last look at us before disappearing. This huge fish left a last impression on all the divers from the USA. We finished the dive by being buzzed by a grey reef shark. That afternoon we returned to Portland Roads, exhilarated, exhausted and excited after 11 days of wonderful diving.
The Far Northern Reefs are without doubt one of the best areas of the Great Barrier Reef. At every site we dived, either new or established, the coral was healthy, the fish life prolific and varied, and there were too many invertebrate species to comprehend. If you want a real diving adventure I would highly recommend heading to the Far Northern Reefs.