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U  N  D  E  R  W  A  T  E  R      I  M  A  G  E  S     A  N  D     A  R  T  I  C  L  E  S


by Nigel Marsh and Helen Rose


Exploratory diving is the diving equivalent of Russian roulette – you don’t know what to expect until you descend and whether the dive site will be a hit or a miss. Over the years we have done a number of exploratory dives and have even found a few good sites, but none as good as the exploratory diving we recently did at the Mackerel Islands.


The Mackerel Islands are a newly opened dive destination in Western Australia, just north of the famous Ningaloo Reef, and off the town of Onslow. Located on Thevenard Island is the resort, Club Thevenard and dive operation, Mackerel Islands Dive (MID).


During our week on the island we did some outstanding diving on the established dive sites like Black Flag, Trap Reef, Greg’s Grotto, Rob’s Bommie and Sultan’s Reef, but with much of the area still unexplored we spent two days looking for new dive sites, with quite a bit of success.


Our first day of exploratory diving was looking for dive sites around Bessers Island. Diving from The Specialist, a 12m purposed built vessel skippered by Richard Burges, we all had our eyes on the charts for interesting terrain. Greg Lowry, our guide from MID, suggested the northwest corner of the island where the chart indicated a step in the terrain. Richard found a likely spot and dropped the anchor, while we eagerly gear up.


Once in the water the visibility was 15m, allowing us to see a flat plain below, but no step in the reef. Reaching the bottom at 16m there wasn’t much to look at, and only a handful of small fish - this was looking like a dud dive. Greg pointed to the west and we followed him, quickly finding a group of small bommies - this was looking better. These bommies were swarming with cardinalfish, coloured by soft corals and home to nudibranchs, coral trout, angelfish and many other reef fish. We then explored a series of bommies and gutters; each decorated by soft corals and gorgonians and found gropers, reef sharks, moray eels and abundant reef fish. As we ventured from bommie to bommie it just kept getting better and better; a group of red emperors, a grey reef shark and schools of snapper and fusiliers. But the highlight was the enormous potato cod that followed us for half the dive. This was a wonderful dive site that we called Tukula Corner, after the friendly potato cod.


We next headed to the north end of Bessers Island and anchored on a group of ledges in 17m. Like all the dive sites we did at the Mackerel Islands this reef was swarming with fish; trevally, cardinalfish, coral trout, fusiliers, rock cod, batfish and mackerel. We explored a series of ledges and caves, finding turtles, sea snakes, stingrays, reef sharks, gropers, lionfish, mantis shrimps and moray eels. This site was also decorated with some beautiful soft corals and sponges, another brilliant dive. We gave this spot the unimaginative name of Bessers Ledges.


One last dive at Bessers Island saw us exploring a collection of bommies off the northeast corner. Again a wonderful variety of reef fish, pelagic fish, reef sharks, stingrays and turtles. We even watched two mobula rays cruising above one of the bommies. We named this site The Scoops, as several of the bommies looked like giant scoops of ice cream.


Our second day of exploratory diving was even better. At Brewis Reef we anchored in shallow water, where the broken rocky bottom varied from five to 9m deep. For over an hour we explored a maze of caves, gutters, arches and bommies that were covered in some of the prettiest corals we have ever seen. Nudies were everywhere amongst the corals and as we investigated the site we found crayfish, turtles, tasselled wobbegongs, reef sharks and even a bull shark. But the masses of fish were unbelievable; schools of snapper, fusiliers, surgeonfish, silver trevally and giant trevally. This site left us speechless and we gave it the name of Stonehenge, as the bommies looked like some ancient stone monument.


It was looking like you could jump in the water anywhere around the Mackerel Islands and have a great dive, which is probably true as the area gets very strong currents, which in turn brings nutrient rich waters flushing through the area and feeding a wealth of marine life.


Our final exploratory dive just had to be a dud we thought, as we had such a good run that our luck had to change, but this final dive was something special. Greg directed Richard to a ledge off Thevenard Island that was known as a fishing spot, but never dived. The current was not too strong, and the visibility 20m as we descended to the ledge, which drops from 16m to 18m. Once on the ledge we were blown away as before us was a mass of fish life. Almost obscuring the ledge were millions of cardinalfish and swimming between them white tip reef sharks, estuary gropers, coral trout, coral cod, snapper, sweetlip, red emperors and over forty rankin cod that had never seen a diver before and proceeded to follow us throughout the dive. As we explored this ledge we also found turtles, sea snakes, reef sharks, crocodilefish, stingrays and were even buzzed by a school of queenfish. We just didn’t want to surface from this magical spot, which Greg named Rankin Road.


There are many more reefs just waiting to be explored at the Mackerel Islands and we are sure that many more spectacular dive sites will be found in this new diving frontier in Western Australia.


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