Judith and John Blashford-Snell in their Dorset home last month.

“With this amazing sunny weather, the garden would have been much better if the deer hadn’t eaten everything.” Judith smiled, unconcerned in a bright orange top, as I looked out at the scorched grass and flowerless beds, the trees shady with the green freshness of the early English summer.

We were sitting on a chintz window seat after lunch in the Dorset home of Judith and Colonel John Blashford-Snell, the army explorer and Nepal aficionado. I rested my coffee cup on a glass-topped cabinet that contained a bewildering jumble of JBS’s many expedition treasures – a tiger’s claw, a shark’s tooth, an old compass, glass beads, a mysterious paw.

“I once did a whole television program talking about bits in there,” remarked John, arms folded across a solid barrel chest. “Mementoes from our Operation Drake and Raleigh voyages as well as scientific excursions to various corners of the world.”

Last month to celebrate the 40th anniversary of these youth adventure training journeys, the brigantine-rigged tall ship, the Eye of the Wind, processed under full sail up the Thames with past trainees, staff and patron Prince Charles on board. I was not amongst them, but was keen to catch up with the aging JBS and had driven several hours to see them.

Other than a slight loss of hearing and a few more grey hairs, I need not have worried–Blashers was undiminished in energy and intent, his upright stance only slightly stooped. “I leave with a group next week for a scientific survey of northern Mongolia, and next spring we’ll see you back in Bardia.” JBS’s trips have investigated Karnali river dolphins, Tarai snakes and a suspected mammoth that was in fact a jungly elephant.

But next year will be without Judith. “These days I prefer to travel on my own,” she confides. “No one ever notices, but it’s no fun being on John’s jaunts unless one has a proper job to do. I’m not good at just being the wife.”

They have been coming to Nepal since the 1970s – back when the country’s unparalleled mountain, river and wildlife resources made it one of Asia’s first pioneer adventure tourism centres, an essential choice for those interested in active holidays. Today we take climbing, trekking, river running, paragliding, bird watching and wildlife safaris for granted as core Nepal attractions, but in those days tourists tended to be more sedate sightseers. Nepal was at the forefront of creating adventure travel and ecotourism, now an established global market.

JBS helped put us on the world map, and some of my more radical opportunities came courtesy of him. Taking a holiday break from Tiger Mountain, I was asked to recce remote northern Papua New Guinea for an Operation Drake voyage, assessing its potential with the Naval Defence Force and Robbie, the enthusiastic 21-year-old son of a major American sponsor.

Robbie didn’t last longer than the tree-lined harbour of Rabaul, East New Britain’s provincial capital,where one sultry afternoon agonising pain from kidney stones had him bouncing off the walls of our borrowed apartment. Robin Cooke,the government volcanologist helped me get him to hospital. Eruptions and earthquakes were so frequent and severe in Rabaul that his official observatory seismograph had fallen off its stand during the last big one. Decades later in 1994 the whole town, precariously sited within a caldera flanked by active volcanoes, would be engulfed in heavy ash fall and destroyed, Robin being amongst the fatalities in this cataclysmic event.

That evening over a drink in the Aussie tavern I naively asked:“What do you guys do in a quake?”Propping up the bar, the locals looked at me, baffled: “Pick up yer beer, mate!”

Without Robbie I had no choice but to proceed alone on the Navy’s patrol boat early next morning. The very large and very Papuan Captain graciously moved out of his tiny cabin for me, and the all-male crew could not have been more polite. We put to sea but it wasn’t long before the engines failed and I was handed over to another similar vessel. That got us a couple more days through the flying fish and past the distant coconut clad volcanic islands of New Ireland, when the same thing happened again.

Near Kavieng we visited an old Planter’s Club that literally rocked on its wooden pillars and crumpled to the ground before my eyes – or am I imagining this episode? Eventually we reached the remote Feni Islands in the Bismarck Archipelago that was our destination, but, having anchored offshore within tantalizing sight of its sandy beaches and gently swaying palms,I was unable to land because the outboard on the dinghy failed to start.

“Don’t worry, it always happens at this time of year!” declared the unlikely-named Colonel Manyana, cheerfully leaning on his desk in a starched white uniform when, back in Port Moresby headquarters and reunited with JBS, we admitted to my having single-handedly disabled the best part of his entire PNG naval defence force. Colonel Manyana grinned shaking his head in sympathy, “It’s the end of our annual budget cycle and without any funds for maintenance the boats are always breaking down.”

I left John and Judith waving farewell from their back door in the English summer sunshine, and drove back through the lengthening shadows past the Stonehenge monoliths – it was nearly the longest day with its midsummer rituals, the ancient power of these places still potent.