Neil's Nile trip

But Neil McGrigor is already planning his next expedition.

The fearless Hampshire explorer intends to swap the heat of Africa for the cold of the Arctic and complete the legendary Northwest Passage in the smallest boat ever used.

Even the murder of one his colleagues on the Nile trip has not put him off.

The 44-year-old father-of-two from Lymington aims to follow in the wake of Norwegian explorer Roald Amundsen.

This year marks the 100th anniversary of Amundsen's successful attempt to become the first person to complete the famous sea route that links the Atlantic and Pacific oceans through Canadian waters and along the coast of Alaska.

In the past 100 years only about 60 vessels have made the hazardous 900-mile voyage.

It was supposed to provide traders with shorter route from Europe to Asia but the sea is frozen over for most of the year.

Now Mr McGrigor is planning to attempt the journey in a tiny Rigid Inflatable Boat (RIB).

He said: "It's exactly 100 years since the first transit of the Northwest Passage and I'd love to do it in a RIB. It's something that's never been done before - people have always used much larger vessels. An expedition would take about 18 months to prepare but probably not that long to achieve."

Mr McGrigor is unlikely to be joined by Cam McLeay and Garth McIntyre, the two Zealanders who accompanied him on his 80-day expedition to find the origins of the Nile.

"The bond of friendship between us is incredibly strong," he said.

Murder

"What we've been through will bind us together for the rest of our lives but each expedition requires a very special mix of people who are best suited to that particular challenge."

The expedition's first attempt to navigate the Nile ended in tragedy last year, when one of their aides was murdered by rebel Ugandan gunmen.

Four months later the explorers returned to Africa to finish what they had begun.

"We'd already completed four fifths of the trip and if we hadn't gone back the expedition would have been a complete waste of time," added Mr McGrigor.

"What happened last year was an isolated incident and it was incredibly unlikely that anything like it would occur again."

Mr McGrigor was proved right but had other dangers to overcome, including crocodiles, ferocious rapids and a lake so big that their 13ft boats were often out of sight of land.

Having identified the Nile's longest tributary, the expedition decided to keep going until they "ran out of water".

The last few miles were some of the toughest. They had to abandon their craft and trek through vegetation so thick they often had to rip it apart to keep track of the river they were navigating.

They finally achieved their goal at the end of last week when they discovered the true source of the Nile, a "very unimpressive" trickle of water in the Nyungwe Forest in Rwanda.

Having completed the first "sea to source" ascent of the world's longest river, Mr McGrigor returned home to hugs and kisses from his family.

Relaxing at his large detached house near the Solent he estimated that the Nile was 4,198 miles long - 66 miles more than previously thought.

He added: "All the data we collected during our trip will have to be verified. After that I will present my findings to the Royal Geographical Society. I feel a huge sense of achievement - more than I ever anticipated."