In the wake of D'Urville

The sounds of the Sounds at sunset. Oars in the rowlocks, knocking a slow rhythm. The quiet slap of water against the motion of the dinghy, blunt bow pushing through deep green sea.

A spotted shag passes close, low to the water, an arrow shooting for its nightly roost. Around the clay point, 100m ahead, a small group of seals sleep and scratch in the last rays of the day, the low light picking out auburn tints in their coats.

I'm on a stealthy sunset visit to observe their languid immobility, and I think I'm unnoticed. So the snort at my elbow makes me jump. White whiskers and dark, saucer-big eyes peer up through the water, then I'm soaked as the watcher turns flipper and dives from view, last seen porpoising out to sea for a night's feeding.

Rowing back along the coastline, the lights of French Pass village begin to dot the inside curve of the bay and fingers of light stretch across the water to pull my small boat to shore.

It's a good end to a great day here at the tip of the South Island, in a tiny village of fishers and farmers tucked into the northern reaches of Pelorus Sound.

It seems just a stone's throw across the turbulent French Pass to D'Urville Island; while far to the west, across Tasman Bay, the snow-capped ranges of west Nelson shine pink in the sunset. To the northeast the challenging strait of Cook rolls and swells, and south lie Admiralty Bay and the hills and waters of the western Marlborough Sounds.

French Pass settlement lies at the end of a gravel road that winds along the spine of the westernmost finger of the Sounds. It's the kind of place that creates an instant rapport; where it's easy to feel you could live, remote from the hustle and grind.

We are here for five days with Danny and Lyn Boulton and their son Shane, to explore the wildlife and seascapes. The Boultons aim to help people to get in touch with nature by getting among it, while Danny provides the soundtrack. He's passionate about this place and its inhabitants - king shags and dusky dolphins, orca, gannets and shearwaters - and is keen to pass his information on to those keen to listen.

The Boultons have lived here for 10 years, refugees from Nelson. In the beginning the focus was on sport fishing and diving, but this has changed over time. As the number of fish and the size of crayfish dropped, their environmental awareness rose. Boulton safaris now include more no-take options.

And Danny is becoming active as an advocate for the environment.

"Longer-term we have to become more appreciative of the things we have here or we will lose them," he says. "I'm not a greenie - it's just common sense."

He'd still love to get a marine reserve somewhere near D'Urville Island, a place he calls "the Poor Knights of the south". And, not one to shy from an argument, he is helping to challenge the tide of marine farms spreading through the Marlborough Sounds. This brings him up against an industry marketing itself as clean and green and environmentally benign. He begs to differ and, over a bowl of snapper-head soup, out come the maps, the research papers, the photos, the facts, the passion.

We hear all this because we're interested and we ask. Mostly Danny lets the place talk for itself.

The itinerary for our five days includes swimming with seals, diving with dolphins and sharks, and bird watching on Te Kakaho Island nature reserve, in the Chetwode group. In the end the weather gods make it two out of four, but that ain't bad. There are walks aplenty, mountain bikes, kayaks and a dinghy for the down-time, and we're lucky to score a morning on the water with a team of Earthwatch Institute-sponsored dolphin researchers from Texas, Tim and Cindy.

Over the past five winters Tim has put in many hours at the helm of a naiad, studying the living and feeding patterns of the Admiralty Bay dolphins both dusky and bottlenose - part of a long-term study on how human activities may impact on dolphins. He has found that some of the French Pass winter animals are the same dolphins that thrill Kaikoura tourists each summer.

The morning we join the researchers is rough and grey, 3m swells are forecast for Sea Area Stephens. Bouncing across to calmer waters on the far side of the bay, we set up transect lines and begin spotting for dorsals. At the end of every run, cold fingers come out of snug gloves to take readings of the water clarity, salinity and temperature, wind speeds, time and position.

Marine farms line the perimeter of the bay, and Tim explains that an application is in for the whole central part as well. His concern is that they may be robbing dusky dolphins of living space - he has never yet come across any animals inside a farm.

And he believes the structures physically interfere with their ability to herd fish into bait balls. Tim wonders what that could mean for the bay's other residents, such as the seabirds that benefit from duskies bringing food to the surface. And if they lose their wintering-over place, will the dolphins move on, and what could that mean for multimillion-dollar Kaikoura tourism?

The rough conditions mean we don't meet any dolphins - their small fins are too hard to spot in the lumpy sea. At lunchtime we're set ashore to join Danny for a seal and dolphin swim. Not far from French Pass a small, rocky island provides a perch for a small group of seals and two king shags. This area on the edge of Cook Strait is the only place in the world where these shags are found, and there are only around 600 birds left. They're deep divers, and have been tracked down to 40m hunting their preferred feed of flounder.

The king shags are more co-operative than the seals, which are in no mood to play today. But conditions have been improving, so Danny calls up the dolphin researchers to see if they can put us on to a pod.

As Murphy's Law dictates, it seems that the moment we stepped off the naiad this morning they hooked up with pod after pod of duskies. Happily they're happy to share. Within minutes we're upon them and three people are over the side, swimming with dolphins. It's mid-winter, the water is 10C cold, but with a pair of dolphins buzzing the swimmers, the swimmers are buzzing.

Back on land, we take a pre-dinner walk to the eponymous stretch of water that makes French Pass such a nautical challenge.

The narrow channel, a little less than 1km wide, races between the mainland and D'Urville Island. The tide can flow at an amazingly rapid seven knots (13km/h) and the uneven terrain of hidden reefs and deep pools forms ship-grabbing eddies and whirlpools.

The pass' Maori name is Te Aumiti. Its European name came from French explorer Dumont D'Urville who, in 1827, spotted what Captain Cook missed, and bounced his ship, the Astrolabe, over the reefs and into Admiralty Bay, saving himself the sail around the outside of the island.

French Pass also used to be home to a second famous traveller, Pelorus Jack, "Kaikai-a-waro". For 24 years from 1888, this rare white Risso's dolphin joined steamers travelling through Admiralty Bay and Pelorus Sound, becoming famous the world over. When Jack disappeared in April 1912, rumours of foul play abounded, but it's probable that he was an old cetacean, and death of natural causes seems likely.

On our last day we load Danny's boat with bread rolls and head for Cook Strait in search of sharks to dive with. Wisps of cloud droop from the top of D'Urville Island and there's a hint of sun on the horizon as we reach our baiting ground. Within a minute, two giant petrels cruise by, checking the oily food trail we're leaking into the ocean, a scent we hope will lure a shark in for our photo shoot. Instead, we spend the day feeding cape pigeons and five black-browed mollymawk that park up along the food slick. They're still fighting over the scraps when the 3m swell for Sea Area Stephens begins to build, encouraging us to head for home.

We'll have to come back. And that will be no hardship.

French Pass Sea Safaris

Case notes

When to go: While French Pass is beautiful at any time of year, you can count on more settled weather outside spring and autumn. Accommodation is limited and bookings are essential. If you plan to go in the high summer season, don't leave it to the last minute.

Where to stay: French Pass Sea Safaris provides fully self-contained accommodation in three beachfront units. These are priced from $88 to $140 for two people, extras $25 to $30 a person. Children under 12 are $18 a night. A number of packages are available.

And if you have the time, try the D'Urville Island Wilderness Resort which offers a beachfront restaurant, bar and accommodation

Getting there: The nearest airports to French Pass are in Nelson, Blenheim, or near Picton. Air New Zealand flights from Auckland to Blenheim (adult return) range from $178 to $478, while Auckland to Nelson fares range from $178 to $498. Air New Zealand's Wellington to Blenheim fares (adult return) begin at $78, and Wellington/Nelson at $98.

Origin Pacific Airways also offers flights from Auckland and Wellington to both Blenheim and Nelson. Auckland to Blenheim adult fares begin at $298 return, with Wellington to Blenheim return fares beginning at $130.

If flying from Wellington, Soundsair provides daily flights to Koromiko, near Picton, from $139 adult return.

If taking the Cook Strait ferry from Wellington, and staying for three nights or less, the best return fares are the Saver Quick Break on the Interislander (slow ferry) at $49 an adult, $179 a car. The best Lynx (fast ferry) return rate is $69 an adult and $199 a car.

If staying away for longer, you need to book separate there-and-back sailings. The best value is a Super Saver on the slow ferry of $25 an adult (one way) and $91 a car. The best Lynx fare is $34 an adult (one way) and $103 a car.

French Pass is a two-hour drive from Nelson, and 2 1/2 hours from Blenheim or Picton.

If driving, you find French Pass by turning north off SH6, just west of Rai Valley, half way between Blenheim and Nelson. The road then winds through farmland and native forest, down through gorgeous bays and along the tops of scenic ridges. Bring lots of film.

If you don't have your own motor, Danny and Lyn of French Pass Sea Safaris can arrange rentals, helicopters or a bus, depending on your budget. Give them a call on (03) 576 5204.

Getting around: The Boultons offer sea kayaking, sport fishing, shark diving, seal and dolphin swimming and mountain biking, as well as walks on both D'Urville and Te Kakaho islands. There are also water- and land-based tours and a water taxi service.

Advisory: While continental breakfasts and meals are available, if you want to self-cater take supplies with you. The French Pass garage stocks essentials, icecreams, diesel, petrol and does dive-tank fills, but don't expect to find a good bottle of dirty red.