Abundant rainfall helps perpetuate this wonderland.
To visualise a blanket of water seven metres thick, take the deep end of a swimming pool at about two metres, and imagine three and a half of them stacked on top of each other.
That's a huge volume of the wet stuff, which also happens to be the average amount of rainfall Fiordland experiences each year. Seven. Metres.
Fresh water plays such a pivotal part in this otherworldly pocket of our planet. It not only carved the mountains and valleys providing today's postcard views at each bend of a fiord or tarn, but its sheer volume also causes tannin- stained rivers andw waterfalls to flow out on top of the salt water below, creating a surface layer that acts like a giant pair of sunglasses, in places 4m or more thick. And this is where the magic happens.
Having scuba-dived and free-dived from the Three Kings off Cape Reinga to Stewart Island in the South, I can confidently say there is nothing comparable to this part of New Zealand underwater. The tinted surface phenomenon produces an environment where light-sensitive organisms, usually found only at great depths, exist happily in the cool-water shallows. Here great fans of black coral, with their white waving arms, some hundreds of years old, create homes for seadragons, brittle stars and the mysterious nudibranchs.
To witness schooling tarakihi along shorelines and hapuku beneath waterfalls is an experience worth the journey alone. But coupling this with sights like entire waterlogged trees standing upright on the bottom with their exposed roots intact, then watching clouds of butterfly perch swim through the ghost-like branches, while huge blue cod cruise the periphery like mini submarines in dark straight lines, and well, you're starting to get the picture of what makes this place such an indelible one. And I haven't even mentioned the nests of crayfish.
In these dual layers of trapped water exist two worlds. In the same location it's possible to not only see steelhead brown trout and fat salmon go squirting past in the top layer, but a short duck dive later find yourself being appraised by a primitive sevengill shark.
Surface again and you are looking at a near vertical snow-capped mountain range rising straight out of the sea, starting just a few metres in front of you.
Those who are weather-blessed enough to venture out of the fiords into open water off the untameable West Coast are treated to a seascape that changes dramatically again.
Above the water it comes alive with seabirds. Wing-tip water-touching mollymawk albatross, with their impeccable plumage are made to look like mere pigeons in the presence of the largest of them all, the wandering albatross. Should you tire of their avian acrobatics, there's the bolshy Buller's albatross attempting to steal your catch next to the boat, or the cape pigeon, a bird that appears much too delicate to exist in this, at times, brutal environment.
Venture a line below and it's all about blue cod, hapuku, tarakihi and rig. Or at the right time of year, small runs of southern bluefin tuna which swim the coast and are susceptible to a lure in just the right place. However don't put anything shiny over the side here, or you will find yourself suddenly competing with the South Island sailfish we call barracouta.
These fanged silver slivers will scissor all of your gear not just two, but often three or four, with not so much as a swivel or sinker spared by the determined marine marauders.
In the late 1980s the NZ Tourist and Publicity office — a precursor to Tourism NZ — ran the slogan "Don't leave town till you've seen the country" to encourage domestic tourism.
With so many New Zealanders still not making what should be an essential Kiwi pilgrimage to a place no column inches, photos or video can ever truly capture, that saying stands as important today as it was then. So if this year is the year you FINALLY book a trip to see for yourself, please, for goodness sake, take a raincoat.
● Clarke Gayford hosts Fish of the Day, Wednesdays, 8pm on Prime.