Jacob Kaambak is a crocodile hunter. Not, you understand, a crocodile hunter in the mould of the late Steve Irwin, who wrestled with reptiles and put them in a zoo.
Kaambak prefers to slip up behind a crocodile in his dugout canoe and stab it between the shoulder blades with his iron-tipped spear. "Then I cut its head off with an axe to kill it."
Later he removes the skin to sell, the meat to eat and even the teeth which can be used as ornaments (though for some reason they seem less highly valued than dog or pig teeth).
His friend Philip Laklom also hunts crocodiles, but he prefers to catch his prey on a fishing line first. "When you have them hooked, you can pull yourself up close for the kill with the spear and then the axe."
These are characters who are used to life in the raw, where nature is respected, even worshipped, but also fought against in the battle for survival.
There was something comforting about having them show me the mighty Sepik River, which snakes its way 1226km through the heart of Papua New Guinea, home to one of the largest populations of the huge saltwater crocodile in the world.
As it happens, during the time I spent with them cruising the river in a dugout canoe I didn't see a lot of crocs because, Philip told me, "They don't like the main river because it is too busy, too noisy, so they stay in the lakes where it is quiet."
That presumably, is why it is safe for the small children who seem to spend much of the day splashing in the river.
During an early morning trip across one of the lakes that sprawl across the river's 70km-wide floodplain we did a couple of times spot red eyes reflected in the torchlight. "See there," said Philip. "That is a crocodile."
Unfortunately we didn't have time to investigate - we had a pre-breakfast date with a bird of paradise - but my interest was noted.
"You can come with us on a crocodile hunt if you wish," said Jacob later. "We have taken other tourists.
"You can watch while we catch the crocodile and kill it and skin it. You can eat some of the meat if you want. There will be many good pictures."
Unfortunately I didn't have the time to take up their offer - though I did later get to eat crocodile meat, which I thought was a little bland - but it does indicate how quickly the Sepik River people have recognised the chance to make a little money by letting tourists get a glimpse of what for them is just a part of daily life but for us is exciting and exotic.
Indeed, Sepik Adventure Tours, with which I was travelling, was started for exactly that reason.
Alois Mateus, Philip's cousin, was working for the Government when his fellow Gala clansmen approached him to complain that the - very few - tourists to visit the Sepik never went to their village of Meno.
"I looked at what some of the tourist companies were doing," he recalled, "and I thought, `I can do that'. So I started this company."
Sepik Adventures now takes about 200 people a year on trips up Papua New Guinea's second largest river, exploring local villages and wildlife in a place where daily life continues much as it has for hundreds of years.
To join one of their adventures you fly into the coastal town of Wewak where Alois, a big man with a bushy beard and an infectious smile, has his base at Surfside Lodge, opposite the airport and on a beautiful swimming beach.
Then there's a four-hour drive, over mostly good roads, through mysterious jungle-clad hills and lively villages with busy roadside markets, to Pagwi, where the road ends - and, with it, most traces of civilisation - and the mighty river begins.
Waiting there were Philip, the company's chief guide, Ivan, our canoe skipper, Kenneth, the cook - all relations of Alois - and the dugout canoe which would be our base for the next few days. This canoe was about 10m long and 1m wide, made in traditional fashion from the trunk of a single tree, but powered by a non-traditional outboard motor and with equally untraditional cane chairs to sit in.
It's a marvellous way to get around, the wind and spray of the journey disguising the crushing humidity and temperatures of around 40C, and the chairs comfortable enough to doze off in.
Not that I did doze off because there were always things to see.
The river is the highway in this region, so it is always full of canoes, a few also powered by outboards but most relying on old-fashioned paddle power; many with just one occupant out fishing, others carrying whole families on an outing; some laden with goods being transported between the roadhead and a village; now and then clusters gathered in the shade of a tree so the occupants could share a smoke, a beetel nut and a chat.
At regular intervals along the way were villages. A few, near Pagwi, have an iron roof or two, much prized for facilitating the collection of drinking water, but the overwhelming majority of houses are built in traditional style, on stilts with palm leaf roofs and woven panel walls.
There was plenty of wildlife - fish eagles diving for prey, turtles popping up their heads for a quick glance, graceful white herons and egrets stalking delicately along the river's edge, songbirds trilling from the trees and fish jumping for insects.
There was an even greater abundance of insect life, especially mosquitoes, many of which carry nasty diseases. This meant I was permanently smeared with a thick layer of repellent (I still got bitten, but I didn't catch anything).
The banks were lined with tall reeds or with what looked to be jungle but was often some family's garden, as many of the lofty trees had been planted for their food, and plots of vegetables were growing underneath.
From time to time we stopped to check on some activity, interesting to me, but part of humdrum daily life for my guides.
When Philip showed me his home at Meno, for instance, a man was doing bark painting, meticulously putting a traditional design on a huge sheet of bark using red, yellow and white clays, watched by an admiring crowd of youngsters (or were they watching the white visitor watch the painting?).
At Aibom village a woman called Alexia was using her powerful hands to knead lumps of clay into pots, ranging from huge fireplaces designed to allow fires to be burned inside the huts to smaller decorative vessels in a design based on an eagle's beak. After completion, she explained, the pots were cured in smoke and baked in the sun. "It makes them very strong."
As we passed Kamanjau village a woman was sitting on the bank washing sago - the staple food in this area - but she was shy and hid behind her dress when I gestured to my camera.
Downstream a family group were taking it in turns to chop the pith out of a sago palm. They weren't shy at all and posed enthusiastically for photos while their pigs took the opportunity to scoff any scraps.
On the edge of Sambri village I spied a man called Lawrence making a canoe with an adze, an axe and a couple of planes. He didn't want his photo taken either, saying, "No, not me, only the canoe, if you want to".
When we arrived in Joseph's village of Palimbe, where he joined us to provide local knowledge, the women had just returned from a fishing expedition and the children were gutting and washing the dozens of fish caught.
After doing their work the children gave a delightful demonstration of how the outside world is reaching even this remote corner by playing a game of "What's the time, Mr Wolf?"
Surprisingly, although fish and sago are the main food in these parts, I was never offered any.
Instead Kenneth used his spirit stove to whip up what I imagine is seen as white man's food: bacon and eggs for breakfast, chicken, onion and salt sandwiches for lunch and dinners of rice, a few packet vegetables and chicken legs or pork steaks.
We slept one night in the relative sophistication of Ambunti Lodge, which Alois' company owns, where I enjoyed a room with its own shower, toilet, fan and electric light, though the power goes off at 9.30pm.
There is, I was told, a Government power generator in the village which theoretically provides round-the-clock electricity but rarely has fuel. The lodge prefers to use the supply provided by a local church which is more reliable but sensibly shuts off at night.
Otherwise, accommodation was in village guesthouses, pretty much like ordinary huts except that we had the added comfort of sleeping mats, mosquito nets and the cane chairs from the canoe. It's not luxury but it's perfectly adequate and I certainly never felt unsafe.
In Palimbe they had even dug a visitors' toilet, with a plastic surround and a wooden seat over the hole, and because it was in a swampy area and infested by mosquitoes, one of the locals insisted on running ahead and spraying it each time I set out to pay a visit.
As that indicates, the people on the Sepik River are very keen indeed to attract more tourists, because of the money they bring.
"We don't need money for food," explained Philip, "because we can grow or catch that for ourselves. But we do need money for school fees and to buy outside goods like petrol for our outboards, clothes and tools. And if you live here, there are not many ways to get money."
* Jim Eagles visited the Sepik River as guest of Air New Zealand, Air Niugini and the Tourism Promotion Authority of Papua New Guinea.