With 50-knot winds whipping up white-capped waves and water tornadoes in the Marlborough Sounds, the weather poses more of a hazard on the Magic Mail Run than any toothy canine, yet Jason offers the following reassuring advice: "In the unlikely event of an emergency, just follow me. I'll be swimming to shore."

On this rain-lashed day, it's difficult to distinguish between the grey sky and stormy sea, but Jason, who seems to enjoy his job more than most people, looks to the heavens and declares: "Lovely, there's nothing like a bit of liquid sunshine."

Located at the top of the South Island, the Marlborough Sounds are a series of drowned river valleys with thickly forested shorelines, deep bays and secluded islands that are best seen from the water. Plenty of tourist boats operate out of Picton, the picturesque former whaling station deep in Queen Charlotte Sound that serves as the launch point for passenger ferries crossing the Cook Strait to Wellington, but joining Jason on his afternoon mail delivery route, which takes about four hours, offers a unique perspective on the dramatic landscape, as well as its history and colourful characters.

Apart from his duties as postman, guide, captain and chief engineer of the Magic Mail Boat, Jason is a raconteur, offering an engaging commentary on the life and times of the Sounds as we bump over the choppy waters to deliver the mail.

"This roller-coaster ride is for free," Jason says as waves buffet the boat with increasing ferocity.

The Magic Mail Boat plies three different routes in Queen Charlotte Sound each twice a week, delivering mail and groceries to households that are largely inaccessible by road. Many residents are retired, but the area is also a haven for authors, artists and dog lovers.

At our next stop, Jason sounds a shrill whistle, which attracts the excited yapping of Ruby and Tuppence, who scurry across a rain-lashed wooden jetty to greet their postman. It takes a few tries to manoeuvre the boat alongside the jetty, before Jason can hand over the mail and dog biscuits, and the rough seas lead to the cancellation of the next delivery to Cape Jackson.

During the journey, he also points out landmarks such as Karaka Point, the long peninsula that was the last Maori stronghold, and the entrance to Tory Channel, whose Maori name means blood-stained water.

A member of the Ngati Kuia tribe, Jason is proud of his Maori heritage.

"We were here when Captain Cook arrived. We were here when Abel Tasman arrived, and we're still here today," he says. "I'm quite proud of that, because Captain Cook traded with my ancestors at Ship Cove."

Captain Cook favoured Ship Cove for its water, timber and trading opportunities with the Maori, and spent many months there during his exploration of New Zealand between 1770 and 1777.

Our one-hour stay is briefer, but provides enough time to visit his memorial, dawdle along the beach and creek and meet weka which, like much of New Zealand's flightless birdlife, are unfazed by our presence.

Accommodation options have improved since Cook sheltered in Ship Cove, and the nearby Bay of Many Coves Resort is one of the Marlborough Sound's finest small luxury hotels.

Guarded by Merlot, a ridgeback-boxer of indeterminate parentage, the resort has a range of one to three-bedroom apartments, each with a full kitchen, smartly furnished living room with a flat-screen television and stereo, and expansive balconies ideal for lazily soaking up the view.

For the restless, there are countless ways to burn energy, such as kayaking, swimming, cruising around the Sounds or exploring the handiwork of the resort's resident massage therapist in the day spa.

What's not to love? Well, at dinner our host, Nick Goodhew, tells us of a guest who was incensed by an alarm waking him at five in the morning, not realising it was a bellbird.

Nick, who lives with his wife, Pip, on their yacht, says they were attracted to the area's natural beauty.

"We can really appreciate the nature, pristine and serene environment of the Sounds, the lack of roads, the native flora and fauna," he says. "The region has the best climate in New Zealand and the wineries of Marlborough are an amazing addition."

Marlborough is certainly one of New Zealand's finest wine regions, and dining in the Foredeck Restaurant is a convivial affair thanks to a cellar stocked with some lovely local drops.

Marlborough also prides itself as the gourmet province of New Zealand, with an abundance of fresh seafood and wild game, as well as chocolate and cheeses, olive oils and stonefruits.

In the hands of executive chef Francisco Sabando De Castillo this local produce is transformed into exquisite dishes such as wagyu beef fillet with king crab, mascarpone and capsicum and tuna ceviche with avocado, ginger and raspberry.

"I'm a big fan of oysters and I can get them pretty much just from the farm to here," Francisco says. "I usually plate them up fresh, as my favourite way, along with the oyster emulsion, which is another of our famous dishes."

The resort's avian alarm sounds at a respectable hour the next day to reveal blue skies and still waters that coax me out of bed and into a kayak. Merlot watches from the jetty as I splash around in circles exploring nearby tiny inlets and beaches.

The deep bays and secluded islands of the Marlborough Sounds are ideal for exploring by water, but the region is also laced with walking and mountain-bike trails for visitors lacking sturdy sea legs.

The 70-kilometre Queen Charlotte Track roams through lush forests, smelling sweetly of honeydew thanks to the feeding habits of a native insect, climbing hills and ducking deep into valleys from Ship Cove to Anakiwa.

The storm-whipped sky of the previous day is a distant memory as I meet hiking guide Jeremy Martin from the Marlborough Sounds Adventure Company to walk the section of the track from Torea Bay to Lochmara Lodge, where a hot shower and my luggage await.

Our walking time is three hours, although Jeremy, who has walked this part of the track more than 200 times, warns it could be longer if the track has turned to mud. However, fortune favours us with a fairly dry path as we make the one-hour climb from the Torea Saddle to the highest point on the Queen Charlotte Track, Shamrock Ridge.

"It's 407 metres high and it's the only time you get literally 360-degree views in every direction," Jeremy says. "On one side you're looking into the opaque green of Kenepuru Sound and down the other side into Queen Charlotte Sound, which is deep blue.

"You can also look back to where you've walked from and you can see most of the rest of where you'll be heading."

The steep slopes dropping down to the water are carpeted in beech trees, ferns, conifers and other deciduous trees, yet Jeremy says it is second-growth forest on land that was stripped bare in the 19th century for farmland. These days, farming is done in the water, with the harvesting of salmon and green mussels.

As we diligently toil towards the summit, Jeremy tells me how the Maori used Torea Saddle as a shortcut to haul their canoes from Queen Charlotte Sound to Kenepuru Sound. A backpack is more than enough weight on my shoulders as we crest the hill to find a jigsaw of lush forests, hills and waterways stretching to the horizon.

It's luckily all downhill to Lochmara Lodge Wildlife Recovery & Arts Centre, which is oriented towards families, with its wildlife breeding programs, art shows,  sculpture trail and outdoor activities designed to wear out small bodies.

Endangered species such as the gecko, kakariki parakeet and longfin eel, which breeds only once at the end of its life, are all VIP guests at the lodge, but my favourite animal encounter occurs the next morning when the water taxi to Picton is waylaid by a pod of dolphins loitering like teenage boys. Sensing an audience, they splash about friskily, duck-diving under the boat and making ripples in the calm water.

Rush hour in the Marlborough Sounds is far from frustrating as shearwaters, shags and countless other seabirds drift overhead and kayaks and boats cruise past us. It is easy to see why Jason reckons he has the best job in the world.

TRIP NOTES

MORE INFORMATION

marlboroughnz.com.

GETTING THERE

Air New Zealand flies daily to Wellington, with connections to Blenheim, from Sydney and Melbourne. See airnewzealand.com.au.

STAYING THERE

A one-bedroom apartment with breakfast at the Bay of Many Coves Resort costs from $492 a night in low season and $780 a night in high season. See bayofmanycoves.co.nz.

A chalet at Lochmara Lodge Wildlife Recovery & Arts Centre starts from $217 a night in low season and $239 a night in high season. See lochmara.co.nz.

TOURING THERE

The Marlborough Sounds Adventure Company offers guided walking and biking tours on the Queen Charlotte Track and kayaking in the Marlborough Sounds. See marlboroughsounds.co.nz.

The Magic Mail Boat follows three different routes, each twice a week, through the Marlborough Sounds. See beachcombercruises.co.nz.

The writer was a guest of Air New Zealand and Destination Marlborough.