Deep beneath the wind-whipped waves Paul and I had cruised slowly through lofty fish-filled shadowed canyons whose dark mysteries unravelled in a kaleidoscope of colour when probed by the powerful beams of our torches. Delicate yellow soft branching corals fought for space with white hydroids, pink and purple flower-like Jewel Anemones and a hundred different splendidly-coloured sponges. Scarlet-hued Red Snapper with huge black eyes moved deeper into their dark over-hang or cave daytime homes for protection as we approached, while clouds of Blue Maomao and a constant flotilla of Wrasse followed behind us in formation. Club Rocks, one kilometre off White Island, is one of my very favourite dive sites and I am always reluctant to leave its underwater splendours and return to the surface.

Mosaic Moray

Near the anchor I knelt on a ledge and prepared my camera rig for the ascent back to the boat switching off the twin strobes and modelling lights and folding the strobe arms to form a compact bundle. From inside a shallow trench alongside me, I caught a flash of white as something moved. It was a Mosaic Moray, an uncommon and very photogenic member of the moray family. Quickly unfolding my strobes I set the camera focus control to minimum distance and gently and slowly lowered the rig into the crevice above the eel. Mosaic Morays are extremely fierce looking - their jaws are long and curved and lined with large closely spaced almost transparent needle sharp teeth. Basically white with a mosaic camouflage patterning of olive green or brown that continues inside their mouth and throat. The effect of this strange livery, together with the 'see through' teeth must be rather confusing to any prospective prey.

A mouth open stance is necessary for the Moray in order to allow water to move over its gill area. Many divers are understandably intimidated by this seemingly aggressive posture and thus keep their distance. In truth all morays, with the possible exception of the mottled moray, are practically harmless and most will not attack even when threatened. This mosaic moray was no exception despite being cornered and surrounded by camera, flashing strobes and bright modelling lights only 30cm away, it made no move towards me. Stretching its mouth fully open and undulating its long thick body and head, it withdrew itself as deep into the crevice as it could manage relying on its camouflage and fearsome appearance for protection.

A slight resistance in the air supply from my regulator indicated a nearly depleted air supply so reluctantly I left the mosaic and headed back to join Paul on the surface. Below I could see that two yellow morays had joined the mosaic moray in its crevice, no doubt attracted by the commotion. Morays, especially the yellow variety, are very common around White Island and on a dive we usually see dozens of them.

Packhorse Crayfish

Back on the boat Irene and David are proudly displaying a good sized Packhorse Crayfish. This larger variety of rock lobster are sometimes found in large numbers around White Island. In the 1960s (when catch limits were more liberal), an expedition from my dive club happened upon a march of these green monsters. Everywhere the divers looked, Packhorse crayfish were to be seen right out in the open. Every cylinder was sucked dry and every sack filled. One, a great chaff sack contained 16 crays and weighed over 80 kilos - it took three divers to get it back to the boat. No march today though, Irene and David's packhorse is the only one brought on board.

Exploring the Crater

Later that day, we landed in Crater Bay from our ship's inflatable onto a cracked and buckled concrete wharf, which once served the old sulphur mine.

During some ancient and violent eruption an entire section of the crater wall some 500 metres wide by 300 metres high, had been blown out leaving a huge wide and open entrance into the main crater only a few metres above sea level. Near this breach in the crater wall are to be found the crumbling buildings and machinery of a long abandoned sulphur mining operation. It seemed hard to imagine that men could actually live and work in this desolate place and yet since 1885 there have been about 30 years of commercial activity inside the White Island crater at various times. The sulphur was used to make fertiliser, for export as sulphur ore and for the manufacture of sulphuric acid.

The first company ceased operations after 15 years in 1900 when conditions on the island became impossible. Then in 1911 another company bought the island, drained a large lake for better access and began mining the sulphur. Before any sulphur could be shipped off the island however, tragedy struck. One night in 1914 a large part of the south-western wall of the crater collapsed creating a massive lahar that swept the boiler house and miner's village together with all the workers into the sea. Ten men disappeared without trace. The only survivor was a cat named Peter who subsequently was honoured by being renamed Peter the Great.

Despite this demonstration of the dangers of living and working inside an active volcano, another company began operations in 1924, quite successfully this time, it's tenure lasting for about 10 years, until a combination of conditions on the island and the economic depression closed the works around 1933.

Corrosive Atmosphere

Since then the factory has remained abandoned and today, besides being a tourist attraction, provides an interesting demonstration on the effects of the sulphurous atmosphere on various building materials and machinery. The concrete walls, though much of them are still standing, have crumbled in places - but the condition of the wooden roof beams and sills are exceptionally good.

Appearing almost as though it has been sandblasted, the timber has probably been preserved by the chemicals in the atmosphere and looks like it would last for thousands of years. Of the corrugated iron, which once roofed the building, hardly a trace remains - cast iron pumps and machinery and steel boilers and hoppers are in the last stages of disintegration, being covered with thick crusts of rust. An old tractor which must have once hauled tons of sulphur from the workings now sits neatly parked within the building, half buried in ash - its solid rubber tyres, like the timber, perfectly preserved.

Named by Captain Cook

Almost 215 years ago to the day of our visit on 1st October 1769, this island was sighted by Captain Cook and named White Island... "because, as such, it always appeared to us." He may have been referring to the pure white column of steam, a constant feature of the island, or to the light colour of the Island itself. Amazingly, it appears that Cook did not realise that the island was actually a volcano despite his officers having conversations with local Bay of Plenty Maoris about the Island. Perhaps, like French explorer Dumond d'Urville, who passed that way one year later, he thought the 'smoke' was from the cooking fires of the natives…

Past Eruptions

Leaving the factory ruins, we headed towards the source of the thick column of steam towering above us which issues forth from the far end of the 1.2 km long greater crater. This steam originates from the 'Christmas crater' formed on December 26, 1976, which has continued to grow both larger and deeper since then. The volcano's activity is usually visible from the Bay of Plenty coast with steam and ash plumes rising as high as 10km on clear, still days.

Despite the great mounds left from the 1914 avalanche the going is relatively easy. Soon the crater floor became relatively flat, consisting of a firm ash base criss-crossed with jagged convoluted channels. Some of these are dry and some carry small trickles of steaming water and are obviously formed in the crater floor when it rains. This floor must alternatively build up during ash eruptions and erode away during rainfalls. Since 1826 there have been over 30 steam and ash eruptions and one in 1977 of andesite lava.

During a photographic expedition to the island in 1968, Kelly Tarlton and Wade Doak were actually photographing in the crater when it erupted with a loud roar. Hurriedly grabbing cameras and film boxes they scurried as fast as they dared across the crater while a constant shower of smoking ash, pumice and particles of lava rained down upon them. Fortunately, they managed to reach the relative shelter of the ruins without harm. A matted mess of sweat and ash, breath heaving, they huddled under sheets of corrugated iron till eventually, when the smoke and steam from the eruption cleared sufficiently, their boat (its gleaming white hull now black with ash) returned to collect them. They lost most of their film in the scramble. That particular series of eruptions subsequently continued for two months and it was thought at the time, by some scientists, that the island was liable to completely blow up.

A Benign Period

No such problem on our visit. The volcano is in one of its benign periods. Never the less we reminded ourselves to be cautious and watchful - for very good reason. Continuing deeper into the crater, the footing became very treacherous, soft and slippery, great piles of solidified mud to climb - the remains of old lahars. The background roar from Christmas crater is noticeably louder and we feel the vibration from its energy through our feet. An area of fumaroles attracts the attention of the shutterbugs amongst our group. Some steam and hiss, some eject mini geysers of boiling water. Here in places a thin hard crust of bright yellow sulphur crystals covered soft mud, crunching under our cautious feet like a pie crust. I paid the price of inattention when a sneaker broke right through the crust in a particularly soft area, immersing my foot in agonisingly hot mud up over my ankle. A quick reaction prevents lasting damage however.

The crater rim soars about 300 metres above us, craggy and barren and not a trace of vegetation to be seen. Nothing could survive for long in this atmosphere. This place feels very alien, very sci fi, like visiting the aftermath of an atomic explosion, or walking on some strange planet. We feel a sense of trepidation, of being in a place where we don't belong, but excitement too - and wonder. There is beauty in its desolation. In spite of this hostile environment, the island is host to a number of bird species including a gannet colony - but none live inside the rim of the crater.

Inside Christmas Crater

As we approached the rim of Christmas crater, the ground rose steeply. Even so, nowhere would it be over 30 m above sea level. The rim is very soft and signs of recent crumbling and scores of faults running parallel to the edge indicated the inadvisability of approaching too close.

I'm determined to get some pictures of whatever is down there. By edging towards the rim as close as I dared and by leaning forward I catch a glimpse of inside the crater but it's totally obscured by a thick layer of steam. Luckily the steam is momentarily pushed aside by the veering wind and I caught a glimpse of a dark yellow lake of sulphur and dozens of roaring vents. A fall down here would be fatal! The crater is very deep, seemingly at least 200 metres to the bottom, way below sea level. I quickly take my pics and retreat.

Steam momentarily covers our group as the wind shifts again. It's acrid and unpleasant to breathe, so we collectively held our breath till it cleared again. A major change in wind direction could possibly asphyxiate a visitor here. The gases are mostly steam, carbon dioxide and sulphur dioxide, with small quantities of chlorine and fluorine. These acid gases can also combine with water in the steam to form acid droplets that can sting the eyes and skin.

Later that day and back on our boat I watched the entire crater erupt with steam during a sudden and heavy downpour and wondered what would happen if the sea entered Christmas crater, perhaps through a weakened area of the outer walls. It is a distinct possibility. With the crater bottom being so far below sea level - perhaps a Krakatoa type explosion would result, with a massive tsunami striking the mainland. I just hope I'm not there if it happens.

Night Dive

That night we dropped anchor in a small bay to the east of Crater Bay. Sheltered from the strong Labour Weekend wind by tall cliffs and the huge mass of the island.

During a day dive we'd found a long cliff face that dropped vertically from the surface to 15 m deep. Just the place for a night dive, navigation is easy and the sea life prolific along such a cliff. Leaving our mates to their after-dinner cans of beer and glasses of wine, Paul and I began the 200 metre surface swim to the north-west point. We'd wisely, though reluctantly, declined even a sip of alcohol. Alcohol and diving don't mix. Not only can it affect judgement, but also tends to dilate the body's blood vessels, making the diver much more susceptible to cold.

Despite the blackness of the night we easily found the point with our torches and were soon descending into the black water. In the shallows the weed is dense and visually unspectacular, thankfully we soon passed the weed band and the edge of the cliff face came into view. The cliff face itself is slightly undercut and as it is shadowed during the day like the deep canyons of Club Rocks, it is free of weed and ablaze with the brilliant colours of thousands of the light-shunning sponges and soft corals in the powerful light from our torches.

This is what makes night diving so spectacular. With the absence of ambient light the diver's attention is completely focussed on what is illuminated by the relatively narrow torch beam - it's somewhat like watching a TV screen in a dark room.

Protected by deep crevices in the cliff face from nocturnal predators are dozens of sleeping reef fish which sluggishly move off when we disturb them. We watched a brilliant Red Pigfish bump its way along the face until it eventually blundered into a deep crevice and disappeared.

Spanish lobsters

Paul nudged my arm and pointed his torch toward a narrow ledge - a Spanish lobster. These strange nocturnal crustaceans rely solely on camouflage for protection during the day - usually hanging upside down in caves or under overhangs. At night they forage for food out in the open. Slow moving and sluggish, they are easily captured by divers and on several occasions I have actually moved one to a more photogenic area where they obligingly sit immobile while I photograph them.

We found ourselves at the start of a long horizontal crevice within which are seemingly dozens of Spanish lobsters. I even managed to photograph three together. Paul picked up one and posed with it - unfortunately stirring up dense clouds of particles in the process, making the chances of a good photo virtually nil. Still it was a nice gesture.

Checking our gauges we found it was time to depart. This was the third dive of the day and because of the level of residual nitrogen in our blood, our time underwater is limited even at the relatively shallow depth of 15 metres. We navigate our way back to the anchor line and hung at three metres for a time as a safety precaution. Out in mid water the torchlight reflects from the shiny sides of hundreds of Blue Maomao. These constantly active fish never rest at night and rely on the protection of numbers for survival from night-time predators.

Thoughts of Sharks

My thoughts turned to sharks as they often do while hanging in the darkness like a human bait. We used to encounter a relatively large number of bronze whalers here around White Island, some of gigantic size with accompanying pilot fish that looked like sprats in comparison. Without exception they all showed only mild interest and never bothered divers, although they at times showed more than a passing interest in a speared and struggling Kingfish...

Over the last six or eight years. encounters have been increasingly rare and I wonder if the pressure of intensive gill netting in the early to mid '70s is the reason.

Shark attack is one of the big fears of novice night divers - but the odds are definitely in favour of the diver. In all of New Zealand dive history no scuba diver I've ever heard of, has ever been attacked and mauled by a shark, let alone at night.

Back on the surface and breathing once more through our snorkels we became aware of the sulphurous atmosphere. On the boat we had become accustomed to the smell but after breathing the pure and highly filtered air from scuba tanks it becomes very noticeable once more.

Regrettably this was our last dive at White Island that trip. The next morning the already marginal wind conditions had worsened and we reluctantly returned to Tauranga. But I certainly hoped to return. The drama of walking inside and diving around an active volcano together with White Island's prolific fish life and crystal clear water would surely bring me back once more.