Northern Arch in the Poor Knights

Saturday 15th was looking very dodgy with regard to the weather. It was forecast for the winds to blow to 35 knots from the southeast, thus making the 12 mile trip out to the Poor Knights Islands Marine Reserve a very bumpy and uncomfortable one. In the end, the decision to go was made by our charter company, Dive Tutukaka, so we loaded 'Bright Arrow' (our boat for the trip) with our rebreathers, twinsets, underwater cameras, toolboxes and what seemed like every other bit of dive gear known to man.

The dive crew for the day were Scott Alker (OC twinset), Mark Gibson (CC Inspo), Greg Lowe (CC Inspo), Pete Mesley (CC Inspo), Gary Palmer (OC twinset), Ian Swan (OC twinset), and myself (CC Inspo). Our skipper for the day was Craig.

Whilst we were loading our gear onto the boat a call came in over the VHF radio requesting assistance from the Tutukaka Coastguard for a diver who had ascended quickly to the surface from the wreck of the HMNZS Waikato (a Leander class frigate sunk for diving off the Ngunguru estuary). They were requesting additional oxygen supplies as a precaution, so we set off to the Waikato and readied our oxygen kit should they require it. The journey there took a matter of minutes from leaving Tutukaka Harbour although the low profile of the moored RIB was difficult to spot initially amoungst the white capping swells. The diver was conscious and receiving oxygen administered by the skipper of the boat, so we stationed Bright Arrow near them should they have needed any additional assistance. Within a few minutes the Tutukaka Coastguard were in attendance, so we requested leave from the scene and left the Coastguard to evacuate the diver.

The journey to Poor Knights was quite rough as we fell into large troughs in the swells, but I positioned myself as far forward in Bright Arrow as possible and could look out at the horizon… a technique that seems to offset the urge to throw up (I've been known to be seasick in the past!) All the dive gear was stowed or tied down on the deck and seemed to be surviving the 50 minute crossing.


Dive 1

The sky was grey with showery clouds, but the large cliffs of the islands provided a welcome contrast. The swell and wind direction dictate which dive sites are accessible at the Poor Knights, and it looked very favourable for Northern Arch in the Tawhiti Rahi Island as being our first dive site. When we got there, Bright Arrow was out of the strong winds and we listened to Craig's dive site briefing. Dive buddy groups were established: Pete and Scott, Gary and Ian, Mark and I. Greg was going to conduct the first part of his dive with Gary and Ian and later join Mark and I when we were in a shallower part of our dive.

Looking down on the surface of the water, I could see it had that dark blue, almost black colour about it which usually means that the visibility would be fantastic. The excitement of dive was brewing up inside me as I pulled on my drysuit… no wait that was just a trapped fart which was quickly and somewhat noisily vented into the cabin. With the drysuit fully vented and zipped up, I pulled on my rebreather and began the 5 minute pre-breathe to activate the scrubber and check that it was working. The controllers read a steady 0.7 across all the displays and I could feel the gases in the loop become moist and warm. Craig assisted me with putting on my side-slung tank, and I was ready to get in the 15ºC water.

At 6m of depth, Mark and I did a bubble check before beginning our descent down the wall. The water was crystal clear and I could see right down into the blue below us. At 40m I paused my descent to check that everything was okay with the gear, made some necessary adjustments, and continued downwards. The slope of the wall took us to 58m where large boulders lay on the volcanic bedrock of the island. There were large finger sponges, and by contrast, some very small black coral trees hanging onto the rocks, but what caught my eye were the swim-throughs in the lava outcrops and I couldn't resist venturing through them. Mark met me on the far side of one such swim-through and then we set off to explore the rest of the archways' secrets.

Slowly ascending the boulder strewn slopes took us to the top of the mound which formed the bottom of the archway at 38m. Here we met up with Gary, Ian and Greg who were traversing back along the western wall. Mark and I pushed against the noticeable currents and found the white sandy beach that disappeared into the blue at the southern end of the arch's floor. Large porae and long finned boar fish swam about ignoring our invasion of their territory. Unfortunately, we didn't see any of the stingrays which often frequent Northern Arch.

Due to the weather threatening to get nasty we were on a short run time of 90 minutes maximum, so our ascent began and we were joined by Greg on the eastern wall for the deco stops. Here I found a beauty of a mosaic moray, wound into tight curls about itself whilst hiding in a small undercut in the wall. Its transparent needle sharp teeth were very evident every time it opened its mouth… I've seen how fast and efficiently these beasts strike at their prey, so I kept my gloveless hands well away. Shortly after leaving the mosaic moray, Mark discovered a small female crayfish (red spiny rock lobster) in a vertical cut.

The wall was covered in colourful sponges, soft corals, large gorgonian coral fans, and was absolutely crawling with life. Small crested blennies peered out from their tiny holes in the rock, triplefins preened their patches of encrusting growth, mature male Sandager's wrasse patrolled their territories, and the almost invisibly camouflaged northern scorpionfish hid on the ledges and in the cracks of the wall.

Poor Mark and Greg must have thought I was mad doing the entire ascent and deco stops with my face pressed up to the busy wall. Unknown to them I was on a mission, and my primary objective was to try and find a pigmy seahorse! I never managed to complete my mission as the little beggar remained illusive to my intensive searching, but there is always next time.

At final stop near Bright Arrow and we met up with Gary and Ian, and we could all see Scott and Pete conducting deco away from the wall at the end of a blob (or also known as a delayed surface marker buoy). After 81 minutes of run time, I was out of the water and back in the boat. During the surface interval, Craig made me a hot cup of spring vegetable soup which I had one sip of and managed to spill the rest over everyone’s dive gear… oops!


Dive 2

The next dive was near Trevor's Rock in a shallow bay with crystal clear water. Ian and I buddied each other for the 56 minute dive. Because my ADV (auto diluent-addition valve) was continually leaking diluent into my loop during the deco on the last dive, so I shut the ADV off with the shut-off valve and manually added diluent as required during this dive. At the deepest depth of 16m we looked for stingrays in the sandy beaches between the large boulders and kelp fields, but never found any. Ian took photos of the assorted nudibranchs that were scattered everywhere around the site and I followed large snapper about. I did spot a fish I hadn’t seen before, a large solitary silver drummer… score!

The journey back to Tutukaka promised to be very rough, so I made a wee bed for myself in the forward cabin and went to sleep. A couple of times I woke with my whole body freefalling back onto the bunk as Bright Arrow fought her way home through the bucking seas. Ian explained later that there were a few times the boat looked like it was going to be pummelled/swamped by huge breaking waves. I woke to the sound of someone being seasick, and looked out the window to see we’d made it back to Tutukaka’s harbour. Poor Greg made it all the way across the rough ocean, only to make a "Technicolor rainbow" when we reached calm waters.
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UPDATE: 6:23 PM, SATURDAY, JULY 22, 2006
• Added pictures to the blog.

My mate Ian Swan took the pictures in this blog on his Olympus C5050Z digital camera and underwater housing. All the pictures were taken in the bay near Trevor's Rock and at a depth between 6 to 15m. The first image shows a rebreather diver, some passing koheru, an inquisitive Sandager's wrasse, and kelp covered lava outcrops.

The second image is of an awesome looking yellow moray with its mouth gaping open. The beastie is curled up in a hole and would have been hiding there waiting for its next meal to naively swim by.

The third image is of the often hard to spot northern scorpionfish. The camouflage is so good that sometimes you get within inches of them before you realise that their sitting there. These fish are “gulpers”, so the mouth extends out at lightning speeds creating a partial vacuum in the water and the prey gets sucked back into its mouth.

The last image is of a snapper. They have large mouths with big teeth and can crush shells with them.
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Photo Credit: Swan, I., 2006 (July 15), Inspiration rebreather diver at the Poor Knights. All rights reserved.
Photo Credit: Swan, I., 2006 (July 15), Yellow moray. All rights reserved.
Photo Credit: Swan, I., 2006 (July 15), Northern scorpionfish. All rights reserved.
Photo Credit: Swan, I., 2006 (July 15), A mature snapper. All rights reserved.