PUNTA ARENAS, Chile (Reuters) - A freezing river swim, a three-day hike through one of the world's most remote mountain ranges and a kayak crossing of the imposing waters of the Beagle Channel: what better way to build up to a marriage proposal?
American couple Jasson Magness and Chelsey Gribbon had raced through a tough, six-day adventure over nearly 600km of southern Chile in the Patagonian Expedition Race.
After their team finished fifth, almost a day behind British second-time winners Helly Hansen-Prunesco, Magness was so moved by the experience he popped the question to Gribbon at the closing ceremony last Friday. Gribbon said yes.
"We went through a lot together on this trek," said Magness. "I realized that if we could make it through the experience we have just had, it meant a lot.
"I was going to ask her at the finish line -- but after six really challenging but really emotional days I thought we were so out of it she might not remember she'd said yes."
The sub-zero temperatures and wild winds that blew across the island of Tierra del Fuego gave the international field of competitors a relentless test of endurance for the eighth annual edition of the race.
The defending champions had their biggest test when they failed to find a rope crossing over a fast-flowing river and had to strip off to swim to the other side.
"We got rapidly swept downstream and there was a real possibility we could have been swept into trees or faster water but we chose the right spot and made it out," said team captain Nicola MacLeod.
Their final challenge was a 20-hour trek to the finish in blizzard conditions. "It was so cold that we had to keep moving through the night otherwise we really would have frozen," said MacLeod.
"We couldn't stop to sleep because we didn't have enough kit and we couldn't stop to eat for more than 30 seconds. We just had to keep on going. But despite all that it was a magical race."
This year's race, which celebrated Chile's bicentenary, began with a 361-km stretch south through the open pampas on bikes and foot, then on into the Darwin mountain range.
Seven of the 14 teams failed to complete the 114-km trek across the mountains and those who did then faced a 46-km journey by kayak across the Beagle Channel before a final 26-km trek, when sun and clear skies returned to ease them to the finish.
Gusts of 100 kph caused the initial kayak leg across the Straits of Magellan to be canceled but the mountain bike sections went ahead and some racers reached speeds of 50 kph without pushing a pedal.
"We have never seen wind like that," said Finland's Noora Pinola, of team Nord Water. You can't even imagine it. Even up hills the bike just kept going -- you didn't have to pedal it."
A thick top crust of snow made a trek across the region's Turba peat bogs particularly difficult.
"Everything in the Turba was totally wet and then it snowed," said Pinola. "I left my shoes outside and in the morning there was 20cm of snow on them.
"I had to dig them out of the snow and put them on again. I already had wet clothes on and then we had to climb in more snow. That was a moment when really I wondered if I would ever manage to finish."
The race is run to raise awareness of the fragile environment in Chilean Patagonia, organizers say on their website (www.patagonianexpeditionrace.com), and teams saw first hand the devastation caused to the Karukinka nature reserve by an invasion of beavers.
"They have certainly altered the environment and it's not what is needed," said MacLeod. "It's changed the whole ecosystem massively, you see that when you go through it, there's dam after dam after dam."
Race organizer Stjepan Pavicic said: "I have been in Patagonia all my life and this is a growing problem. We hope that increasing awareness of this issue can help find a solution."
Finn Tuomas Sovijarvi was forced to quit after the main trekking section, but not before walking nearly 100 kms in excruciating pain.
The Nord Water racer had slipped on rocks in a remote valley halfway through the Darwin Range and suffered a haematoma in his leg.
"I slipped on a rock that was covered with water and I hit my leg quite hard on another rock," Sovijarvi said.
"I didn't think it was serious, so I continued walking and my team mates carried my things. I didn't even think to quit, but the pain was so great I almost passed out a few times."
Many racers lost toe-nails and Spanish team Air Europa Bimont did well to finish second after competitor Uxue Fraile suffered a twisted knee.
Team Switzerland and German team Herbertz finished joint third with GearJunkie.com -- the team of Magness and Gribbon -- fifth. Canadians Untamed New England were sixth and Japan's East Wind, the first Asian team to compete, seventh.
Two teams -- Britain's Fast and Light and American Almost Famous -- stopped because of an energy-sapping stomach illness.
American team Eddie Bauer, whose two younger members Druce Finlay and Valentin Chapa were stuck in the mountains for three days in last year's race, missed the cut-off.
The team were put together at short notice and Finlay said: "We just couldn't pull it off and I felt hugely disappointed, but it's hard to race with a new crew and sometimes they don't gel correctly. But we'll come back next year."
Editing by Clare Fallon