"Can you believe that such beauty exists?!"

You don't know what genuine fear is, until you perform solo with a musical instrument in front of a sizable live audience.

On Saturday night, I played part of a J.S Bach flute sonata to an audience at the Grey Lynn Community Centre in Auckland. This was my third public performance, and trust me when I tell you that it was a pretty terrifying experience. There were about 100 folk there, and it was part of a fund-raiser for the Auckland Buddhist Centre.

J.S. Bach is one of nature's true mysteries. A humble man from a family of musicians whose parents both died when he was ten ... he went on to become the greatest musician the world had ever known. His life was stitched with tragedy - ten of his children died in infancy ... and yet he created a vast body of music that transfixes with its power.

His flute sonatas are finely-wrought puzzles of intricacy. As a musician you play them in a state of awe, hoping to offer some kind of fidelity to the precision and beauty revealed there.

The flute uses both its own body and the skull of the flautist as resonating chambers ... so you find that your entire head is echoing with this sublime music.

I first started playing these sonatas long ago with my pianist father, who asked me why I chose the most difficult pieces in the baroque repertoire. 'Because they're there!' I shouted, modesty repeating the words of George Mallory when asked why he attempted Everest. We would often finish the fiendish first movement of the B Minor sonata - all 118 bars of it - a couple of bars apart, and this was accompanied by quite a bit of laughter.

Sarabande: JS Bach's A Minor flute sonata

To a fairly shy person like myself, the notion of playing this kind of music to an audience of skeptical Aucklanders kept me awake at night for some time before the event. During the actual performance, my fingers kept slipping off the keys with perspiration.

I asked myself why I did it, and I came to the surprising conclusion - surprising to me at least - that I got up in front of that audience because I found it so frightening.

But there was something else, more profound in this offering that helped me stand up there on that musical cliff edge ... something to do with the mystery of the music itself; its astonishing vitality and power after 300 years. It was chance to get up in front of a room of 100 people and exclaim in exhilaration ...

"Look! Listen!"

"Can you believe that such beauty exists!!"

Deep diving a sea cave

Today we descended to a depth of 75 feet and eased our way into a sinuous sea cave beneath the limestone cliffs of 'Eua ... entering this place provokes a thrill that courses through the whole body and creates a galvanising sense of fully living each fraction of a second. The quiet at this depth is profound ... just the hoarse rhythm of my own breathing, and the echo of my companion's bubble stream. Above us, the roof of the cave steadily closed in, a sensation of increasing entrapment. High overhead, in a breach of the cave roof, we could see sunlight filtering down towards us.

The seabed was littered with piles of rubble from the cliffs above. Over the aeons, spurred by the frequent earthquakes on 'Eua, sections of the ceiling had tumbled into the cave, a reminder of the unstable nature of the geology in these parts.

'Eua sea cave

In the distance we could hear the singing of hump-back whales in the straits of 'Eua. My dive buddy, Tani, a stocky Tongan, was waving a torch, which lit up the black interior of the cave, and we moved steadily into its depths, hoping to find rare fish, buried treasure, perhaps a skeleton ...

The whole experience was made more surreal by the fact that it was Tani who had discovered the body of my friend Wolfgang tied to the seabed a short way up the same reef (see 'Wolfgang's Last Dive' below).

At this depth the body burns oxygen at a fair pace, and I was aware as we penetrated further into the cave of the diminishing supply in my tank. On a previous dive on this reef I had run out of air due to a faulty indicator and come to the surface too quickly - something I didn't want to repeat: Nitrogen bubbles can form in the blood and result in crippling and agonising injuries.

'Eua is on the edge of the Tongan Trench, a deep rift in the earth's crust that plunges south to Antarctica, and up which the humpback whales migrate each year: a whale super highway. 'Eua itself was thrust up by seismic activity 40 million years ago, and its elevated coral reefs are honey-combed with caves and sink holes, some of unimaginable depths.

The reefs are encrusted with a smorgasbord of corals ... candy pinks, chrome yellows ... delicate lavender blues ... like the execution of a divine sculpture garden. I have been diving these reefs for years now, and they never cease to amaze with their improbable perfection.

Just the hoarse rhythm of my breathing

As much joy, is being taken diving by a bunch of magnetic Tongans, I have grown to know and love. Finau, a stocky forty year old, whose gentle eyes belie his immense knowledge of the sea, marine diesels, diving, carpentry, engineering and ... tropical cuisine. Sam, a former commander in the Tongan navy ... a massive man, built like Jonah Lomu, who like Finau disguises his equally impressive expertise with a quiet-spoken humility.

Afterwards, devouring pizzas created in the home-made pizza oven at Ovava Tree Lodge, even allowing for the effects of post-dive euphoria, I realised this was one of my favourite spots on earth.

Sex ballet for humpbacks

This morning we were in the open ocean, and below us, three massive humpback whales were locked in a mating dance ... their flippers stroking each other's bodies in a tender display of fore-play, cetacean style.

Sex at a depth of twenty metres is a languid affair, without obvious passion, but with a balletic grace that belies the 40 tonne weight of the animals. Their great white ribbed bellies were turned upwards towards us, a group of humans splayed out on the ceiling of their cerulean world in wet-suits and snorkels.

Love in the deep blue

We had left the Tongan island of 'Eua an hour before, and the first whales we came upon were skittish and left the scene as soon as we threw ourselves into the water from our aluminium runabout.

But this menage a trois, two males and a female, seemed unphased by our presence. Occasionally they surfaced, perhaps ten metres away, bodies as big as a bus - obsidian black on the upside, shimmering white beneath.

Their heavy-lidded, seductress eyes seemed half-fixed upon us, and half-fixed on the ballet they were executing in clear blue water. On the occasions they rose to the surface, their great tail flukes smacked the water like a crack from a pistol. Several times a male - intending to impress the female, leaped from the water ('breaching') with an exhibitionism that seemed truly mammalian.

The males sing complex, extended songs while mating, signalling their credentials to the female, who listens to the call, and makes her choice accordingly.

Incredibly, this trio rumpty-tumpteed for three-quarters of an hour beneath us, an apparent exercise in playfulness that seemed as human as it was cetacean.

Humpback migrate every year from the Antarctic regions, where they feast on krill, fattening themselves for the fastening months in the warm waters off Tonga. In these regions, they mate and give birth.

Wolfgang's Last Dive

There are not many scuba instructors who tie themselves to the sea bed on an incoming tide, but then Wolfgang Borner was an unusual man.

Today I visited his grave, an unadorned block of concrete, without inscription, in a graveyard full of the elaborate, flower-covered sand-mounds of local Tongans.

When I first met him, he had just begun construction of a row of chalets on a coral ridge above the ocean on the island of 'Eua. He had a sawmill from Sears and Roebuck on his back lawn, and fashioned tens of thousands of planks from off-cuts of the island's logging industry.

He had persuaded the loggers to give him the wood for free. Each of the chalets featured minutely worked wooden shutters, and hand-carved doors and lintels. Between 2009 and 2015 this stylish row of red cedar huts extended further along the escarpment overlooking the harbour. He also built a large dining room, and a vast shed to cover his sawmill. When he finished this project, he immediately began construction of a 21 foot catamaran in which he would 'sail into the sunset'.

I returned every year for four years to 'Eua, as the row of fale crept along the ridge above Ohonua Harbour, sometimes camping on the floor of a half-completed hut, while I learned scuba diving from Wolfgang. He was an impatient, exacting teacher, who reprimanded me for my tendency to float to the surface. Only by girthing me in many pounds of lead, could he get me to stay on the bottom.

He kept bees on the escarpment next to the huts, and presented comb honey to his guests. Almost as good was his papaya and passion-fruit jam; his oven-roasted arabica coffee; his cinnamon and chocolate pancakes, and the elaborate pizzas he made in his home-cast pizza oven. Friday night was pizza night, and locals, including a bevy of Mormon missionaries, would converge from around the island to feast on Wolfgang's fare.

Wolfgang had been a wealthy man in the former East Germany under Soviet rule, where he ran a commercial sawmill, and owned a multi-story house. Visiting an aunt in the West, he had been tempted to escape, but drank a litre of vodka and steeled himself to return to his wife and daughter.

When the Wall came down, Wolfgang fled Berlin for Honduras to run a dive centre, where his problems really begun. He ran out of money, his dive boat was damaged, and he began to have hallucinatory dreams. His wife and daughter, soured by this precarious life and his pungent, prophetic visions, abandoned him and returned to Germany. His place in Honduras was infected with demons he told me, who appeared in the guise of a wild red dog, and it was only through Jesus that he was able to keep them at bay.

As well as being a scuba instructor, Wolf was also an adventurous sailor, a gifted and creative mechanic, and a relentless pursuer of the hump-backed whales that came to 'Eua each winter to breed and give birth. One year, I brought him a suitcase stuffed with fins and snorkels. Another year I gifted him a computer, which he cast in the ocean when he discovered his young Tongan assistant watching pornography.

Around a fireplace made out of rough blocks of coral, Wolfgang would open a bottle of whiskey, and in passionate tones, explain how the promise of eternal life brought him profound joy and exaltation. Thus was ordinary life made bearable. Often, in the midst of these speeches, his guests would get up and leave. It was when the monologues began over breakfast, that I realised things were moving to crisis point.

Final opus - 'Kleines Boot' is complete

On my final visit in winter 2015, he sported a biblical grey beard, and his hand shook when he poured my coffee in the morning. He was putting the finishing touches to 'Kleines Boot', the ornate catamaran that was his final opus.

The Tonga Times reported the Wolfgang had indeed sailed the 41 kilometre stretch of ocean to the main island of Tongatapu. He told reporters that the boat was too small for ocean transport, and he planned a monster craft for the hundreds of kilometres to the island group of Vava'u. Two months later, he was dead.

His employee at the Ovava Tree Lodge, Tani, told me that Wolfgang had disappeared at Xmas 2015, and three days later, fishing for a New Year banquet, he had found the German on the seabed, in flippers, snorkel and mask. He had tied his feet to a large rock.

It was a typically flamboyant gesture from a man who lived by extremes; a Berliner who rarely compromised in the execution of his plans ... and a man who brought to the tiny island of 'Eua, a memorable cargo of skill, passion and eccentricity.