One moment, I'm floating face-down in the water on the lookout for any sign of Flipper. The next, 40-odd dusky dolphins overtake me in a flash of underwater grace, wave after wave of darting figures and flicking tails.

I raise my head, about-face and wave to the other swimmers, but all I can see is a guide on the boat, laughing riotously at the look of astonishment on my face.

It's a look many staff at Encounter Kaikoura are used to. And it's as common as the pods of hundreds of duskies cavorting in the cool waters in South Bay, just off the Kaikoura Peninsula.

Against the backdrop of the snow-capped Kaikoura Ranges, these offshore waters are known nationally and internationally as whale-country. But while the whale experience is an onlooker's paradise, swimming with dolphins is an intimate, interactive experience.

If they notice you, that is. Encounter staff start the day by doing a great job of lowering expectations. Dolphins can be curious, they say, but they can also be snobs and ignore you.

But why? Are we so ugly as a species? Do we have so little in common? Modern man, after all, is very much like a dolphin.

"Duskies pretty much feed, sleep and shag," says Tony, one of our three guides. Therefore for the best interaction, I reason, we should look as tasty, sleepy and sexy as possible.

A documentary team, Tony continues, once witnessed a female dolphin get busy with three male dolphins five times in less than two minutes.

He's never heard of dolphins getting busy with humans - but if a dusky swims up to you belly-first, you're in.

The first problem is that full-length wetsuits are about as saucy as a rotund politician in a celebrity dancing competition. But another method to attract them, we're told, is to make high-pitched sounds.

Predictably, the shrilling commences as soon as we hit the water. It's odd to see grown-ups resembling a pack of pre-schoolers in a world of chocolate - excited, energetic, and squealing without shame nor rest.

The crew had found a perfect spot, a few kilometres from shore. I submerge my head under the cool 14C waters, humming my underwater lullaby, and am instantly surrounded by dolphins. Dozens of them, swarming in a delightful, mesmerising dance.

The squealing becomes quite involuntary.

They approach from all angles leaping into the air from right beside us, before diving back down for another boogie.

They move through the water with impressive speed and manoeuvrability, then swim off as quickly as they'd appeared, leaving us rejected.

I head in a different direction and become isolated, just as a pod swarm me from behind, leaving me motionless with an amazed look on my face. It's the Kaikoura equivalent of running with the bulls, only underwater and without the danger of being crushed.

Several duskies circle back and eyeball me as they swim circles around me - no one really knows why they do this - leaving me in a dizzying, graceless spin.

Trying to lure them is unnecessary. Just floating harmlessly is an invitation to play chicken. They emerge from a hazy 5m visibility and swim directly at us, only to dart off at the last second while we float in a state of stunned, frozen delight.

It's tempting to reach out to stroke their sleek torsos, but, as instructed, we resist.

Usually about 70kg and about 1.8m long, the dusky is dark grey and has white trails down its sides to its tail, which propels it through the water at up to 30km/h.

Its throat and belly are white which contrasts with a dark beak and light grey eye-shadow.

Duskies have an almost tranquil sorrow to them, as if forever swimming, eating and shagging has doomed them to an unfulfilling existence.

They have a short attention span, too, and suddenly disappear. Off to another dance club. One without these strange, masked beings with their even stranger squeals.

The dolphins, clearly, had found us irresistible. Why else would they have frolicked with us for an hour?

It's more to do with the food, says Tony. The bay is one of the best feeding grounds for duskies, fur seals, giant sperm whales and a host of seabirds.

Just offshore, the seabed drops sharply into a series of deep gullies: the Kowhai Canyons east of the peninsula, the Conway Trough to the south, and the Kaikoura Canyon, a 60km-long, one-mile-deep trench.

Two oceanic rivers meet in the bay - the warm current from the east and a colder one from the south - and converge to propel all kinds of deep-ocean nutrients to the surface, and provide for a vibrant marine-life microcosm.

The tucker must be good. The wandering albatross comes all the way from the Auckland Islands - a 1000km flight - to feed on delicious delights, only to fly back and regurgitate it for the young ones.

The trip wouldn't be worth it for B-grade cuisine, says local guide Gary Melville, who runs the albatross trip at Encounter.

Not far from where the swimmers frolic with duskies, Gary reveals the secret: the foulest-smelling concoction - "mainly fish livers and other bits" - in existence. Within seconds of dropping it in the water, a cacophony of loud squawking announce the arrival of the first seabird battalion, complete with albatrosses, giant petrels and gulls.

The larger birds control the prize while smaller species bark harmless disapproval from the sidelines.

The giant petrels waste little time in asserting rank, throwing their wings out in a grand gesture and sounding a throaty cry.

The mighty albatross, however, is not to be upstaged. Swooping in from the north in full cry, with its 3.63m-wingspan, it quickly bats the petrels away and starts feasting, unchallenged. It reinforces its royal status by occasionally prodding the petrels with its superior beak.

The only challenge comes from other wanderers, which psyche themselves up from several feet away before spreading their wings and barging at the king.

When all the livers are gone, we make our way home around Barney's Rock, a popular hangout for countless seals, gulls and shags.

Baby seals bask in the sunshine and, when their tummies start to rumble, they dive into the watery all-you-can-eat buffet, enjoying a lazy afternoon in the deep south's best restaurant and playground.

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GETTING THERE
Air New Zealand has regular flights to Blenheim and Christchurch. See www.airnz.co.nz or phone 0800 737 000. To hire a car from Pegasus Rental Cars see www.rentalcars.co.nz or ph 0800 80 35 80

ACCOMMODATION
Hapuku Lodge, www.hapukulodge.com or call 0800 kaikoura

ACTIVITIES
Find out more about Encounter Kaikoura at www.encounterkaikoura.co.nz or ph 0800 733 365.
Glenstrae Farm 4-wheel adventure tours are on the web at www.4wheeladventures.co.nz.
Discover Kaikoura's Maori Tours at www.maoritours.co.nz or ph (03) 319 5567.

*Derek Cheng flew to Kaikoura with Air New Zealand, and was hosted by Pegasus Car Rentals and Hapuku Lodge.