Horn Rock

Diving the Hauraki Gulf: Horn Rock

by Jenny and Tony Enderby


Right on Auckland’s doorstep lies the Hauraki Gulf, known throughout the world as a boating paradise. It also offers some great dive sites, both on the coast and around the many islands and rocks. The Gulf offers visibility over 20 metres, and due to the easterlies this year it is at its best. It also offers something for everyone. From the underwater photographer to the cray diver or spearfisherman – the Hauraki Gulf has it all. Strangely, like so many things in your own back yard, it is easy to overlook and go somewhere else to dive. Over the next few issues we will explore some of the region’s many dive sites: what each has to offer, the charter boats which service them and any other points of interest. Our first site is Horn Rock.

To many divers, Horn Rock has a certain mystique. Most have heard of it, but few seem to know where it is or have actually dived it. Rumours of huge currents, huge crayfish, and huge kingfish always seem to accompany any mention of Horn Rock. Horn Rock is actually a large area of rough ground between Little Barrier and Great Barrier. Only one small rock breaks the surface; the rest of the site lies between 10 and 20 metres, dropping off the edges to over 40 metres.

Midweek during a recent holiday, we joined the charter boat Divercity, leaving from Leigh Harbour. We were lucky to have one of those magic days, with no wind, clear blue sky, and underwater visibility over 20 metres. With these good conditions, the decision was made to dive the ‘Horn’. We anchored in about 20 metres and from the deck we could clearly make out the white sandy areas between the rocks. We were aware from experience of the possible currents in the area, and the Divercity crew reiterated this. Everyone on board was pretty experienced, so no problems were expected. (In fact, half the divers were even older than Tony!) The inflatable pickup boat was also available if needed.

On entering the water, it turned out the current wasn’t too bad and we drifted down into one of the many canyons which makeup this area. We reached the sandy bottom at about 20 metres and looked up at the sheer rock walls of the surrounding reefs. Disappointingly, there was not the life we would have expected on the walls, although there were some sponges and other encrusting invertebrate life. Above us the boat’s silhouette stood out against the blue sky and clear water. This was a nice place to be, certainly nothing like the stories of what a hard dive it is. Maybe we just struck the right day.

Large numbers of school fish drifted around above us: demoiselles by the thousand, sweep, blue maomao, trevally, mackerel, and closer to the sea floor red moki, goatfish and wrasses. The occasional john dory cruised in for a look and then drifted off, nearly invisible against the blue when they turned side on. In amongst the eklonia kelp, scarlet wrasse and goatfish swam in large numbers. Some of the night fish like slender roughy and big eye were out in the open, retreating into their holes only when we approached close. Other holes were home to what many on board were hunting for … crayfish. There were quite a few hidden deep in the rocks. Strangely, we didn’t see any moray eels, although it was the sort of rocky terrain they should live in. Evidence of line fishing was all around, with entangled nylon, swivels and hooks common. This was definitely a dive on which to carry a knife with a good sharp blade in case of entanglement.

We followed a circular dive pattern and crossed many of the canyons that dropped from 12-15 metres at the top down to around 25 metres on the sand. Above us the school fish swirled and the occasional kingie passed through. Several small stingrays cruised over the sandy floor, one of which had obviously fallen prey to a fishing line at some stage. It had no tail; most probably it was cut off by a fisherman trying to retrieve his gear without getting barbed. At least the ray lived to tell the tale and showed no sign of discomfort. The stingrays didn’t seem to be worried by divers. In one close encounter, a medium-sized one cruised right underneath Jenny. In photographing it she had difficulty keeping her legs out of the picture.

Around some of the big boulders we saw large numbers of red moki hovering. Every so often, one would become aggressive and chase some of the others off, then return to the same spot. Their colours varied from very light with pale banding to almost completely dark brown. This seemed to be some sort of mating coloration. This was one of those dives where we just slowly swam and enjoyed being there. It was nice to just drift along taking the occasional photograph. A few reasonable-sized crays in a hole was also a chance for an unsuccessful attempt at getting dinner. We were now 35 minutes into the dive and the computer was showing us that the end of our dive time was getting near. There were a few more crays in that area but it was better to begin to head back, doing a deco stop either mid water or on the anchor line. The great visibility also meant we could use the bottom as a reference on a mid water deco stop, and not end up a few hundred metres away from where we started the ascent.

It was nice to see Divercity only 50 metres away across an oily flat surface. Getting back on board this boat is great. Although she doesn’t actually crane you aboard (something sadly needed on charter boats for the over-50’s … well, one of us is!) the submerged stern platform makes it very easy. The other divers showed their spoils from the dive; there were quite a few good-sized crayfish, with most divers having something to take home. This was a neat dive and hopefully it won’t be long before we make it back for another. Our second dive was to be at Little Barrier, only a short trip away. This was the sort of day you dream about: flat sea, blue sky, a good boat and good company. We’ve got to do it again before the blue water disappears.

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