This is my first visit to Papua New Guinea, and also my first cruise. Fellow passenger Yvonne thinks I may have picked the wrong one. "This is as upmarket as cruise ships get. You won't want to travel on an ordinary ship after Orion." She has a point. The "luxury expedition ship" MV Orion's 338ft encompasses four decks of staterooms (cabins), bars and lounges, fitted with miles of polished wood and brass. Opulence is one thing, but the point of an expedition ship is where it takes you – in this case, through the Bismarck Sea, along the easterly coastline of the Papua New Guinea mainland and on down to the islands of Milne Bay Province.
Of the few locations left in the world billed as "the last frontier" for tourists, Papua New Guinea has perhaps the strongest claim. The mountainous, densely forested core of the main island is hard to penetrate. Remote villages are connected by treacherous roads, muddy tracks and isolated airstrips, so travelling by ship around the coast makes sense, but it brings with it moments where extreme luxury sits in surreal contrast with the most basic kind of village life.
After a connecting flight from Cairns in North Queensland, Orion's passengers muster in the port town of Rabaul on the island of New Britain. Here, Mount Tavurvur is putting on a show. Rabaul was one of the country's largest population centres until 1994, when an eruption of nearby volcanoes Tavurvur and Vulcan blanketed the area in volcanic ash, forcing the populace to establish a new provincial capital 12 miles down the road.
Mount Tavurvur has menaced Blanche Bay ever since, belching plumes of ash big enough to be visible even from our ship, docked more than a mile away. It makes a dramatic back-drop to our champagne launch party.
For two nights and a day we sail north-west to the Papua New Guinea mainland. The rough sea makes things uncomfortable, even when ensconced in an enormous stateroom and gigantic bed. It's a relief when we drop anchor near the entrance to the mighty Sepik river. Expedition ships are designed to get you to places like this, and Orion carries eight inflatable speedboats for the purpose.
We're expected at Watam, a village of 300 people near the mouth of the Sepik, and one of its six clan chiefs leads a band of singers and drummers to meet us. Although dug-out paddle canoes are a common sight on the Sepik, the 40hp motor powering the welcome party's 20ft aluminium runabout more easily keeps pace with our boats as we pull in to shore.
We're welcomed with singing, dancing and a 12-man ceremonial "dragon". Orion is one of two cruise ships that visit the Sepik region once a year, and people travel from villages upriver to sell their woodcarvings, woven bags and baskets, necklaces and ceremonial headdresses. There's no bargaining, items are offered at "first price" with a buyer's option of asking for "second price", which may be a little or a lot less. In any case, it signals the end of negotiations.
Our next mainland stop is Madang, a town of 27,000 people that saw heavy fighting during the Second World War. A dive to a wrecked plane is on the ship's tour itinerary, but fellow passengers Amelia and Peter suggest we walk into town and organise a dive for ourselves. Within an hour we're zooming off to nearby Pig Island, where we spend an hour drifting along a sloping coral shelf in 29C water. We were travelling late in the rainy season (from January to March), so underwater visibility was not the best, but there were plenty of brilliantly coloured tropical fish on display, and even a green moray eel.
Papua New Guinea's undersea world is a prime attraction of the Orion cruise. As we approach the tiny cluster of atolls known as the Tami Islands, our expedition guide talks the place up. "The best snorkelling I've ever done is in the Solomon Islands, but the place we're visiting today comes pretty close," he says. Another village welcome is laid on when we land – a group of around 30 men, women and children greet us wearing grass skirts and feather headdresses. These ceremonies can be awkward, with hosts and visitors alike acutely aware of the cultural divide separating them.
On this occasion, a cheerful song-and-dance recital ends when a fearsomely decorated man misses the finish and launches on his own into a non-existent final verse, prompting embarrassed giggles from his fellow performers – a perfect reminder that it's the gaffes and fumbles that most naturally bind us together.
A day on a nearby uninhabited atoll, complete with beach barbecue, cold beer, champagne and ice-cream, is about as good as one can reasonably expect life to get. We snorkel for hours over stunning forests of stag-horn coral tinted emerald green, sunset orange and royal purple.
The most dramatic destination of the next few days is Tufi on Cape Nelson, where long fingers of densely vegetated volcanic lava, known as rias, jut into the ocean. A few small villages are dotted around, and Tufi Dive Resort accommodates any scuba-enthused tourists who make it to this part of the world. It's easy to see the attraction: no roads in or out, diving every day and one languid location in which to eat, drink, sleep and socialise. A few of us take a guided walk along a muddy track to the end of one of the rias, where we get a fine view of the bizarre lava landforms fringed by mangroves and dotted with shallow coral reefs.
Dining onboard Orion is a daily event in itself, thanks to a menu designed by Serge Dansereau, proprietor of Sydney's Bathers' Pavilion restaurant. On evenings when the chefs aren't working up an extravagant outdoor seafood barbecue, they're bringing to life dishes such as slow-cooked lamb loin with aubergine polenta, swordfish with French lentils and water spinach, or tuna sashimi with whitebait tempura seaweed salad. Coupled with a spirited selection of Australian and New Zealand wines, it's a gastronomic marathon over 11 days for which there should probably be some sort of training programme.
Our final stops are the isles of Fergusson and Samarai. The former boasts some impressive hot-springs and geysers; the people of Dei Dei village are also adept at speaking English, which is unusual in Papua New Guinea and the result of missionary education over the years. Samarai still has signs of colonial-era commerce in its dilapidated wharves, warehouses, and overgrown but still grand boulevards. Keeping Samarai out of Japanese hands during the war was a close-run thing, and much of its infrastructure was destroyed by Allied forces for fear of it becoming a strategic base for further Japanese expansion into the Pacific.
It takes two nights and a day sailing south before we arrive back at Cairns, so there's time to review some culture and history in the ship's library, and eat several more stellar meals. It's been in every possible sense a luxury expedition and a privileged opportunity to make acquaintance with one of the world's most fascinating and still least-known regions. It may be remote and mysterious, but Papua New Guinea's landscapes, cultures and undersea world offer rewards not readily found anywhere else on Earth.
Travel essentials: Papua New Guinea
The writer travelled with Orion Cruises (020-7399 7620; orionexpeditions.com ) which has 11-night Papua New Guinea cruises departing 11 and 22 October from £5,125 per person assuming two sharing, not including international flights, but including the one-way charter flight from Cairns to Rabaul.