On a follow-up call in late December from his farm in the Dolomites, Mr. Messner, a Montblanc ambassador since 2022, said the watch, a limited edition of 1,990 pieces, was meaningful to him for a couple of reasons. Not only was it inspired by his father’s historic 1,740-mile, 96-day crossing of the Antarctic landmass in 1990, when the elder Mr. Messner and the German explorer Arved Fuchs became the first men to cross the continent by foot without animal or motorized support, it also kept him company on his own Antarctic journey.
“Running a marathon is very different from crossing a continent, but you feel it,” he said. “It was very emotional.”
The idea to run the marathon was Mr. Lecamp’s. An ultra-trail runner and veteran marathoner, the Swiss watch executive has participated twice in an ice marathon across Lake Baikal in Russia, in 2018 and 2019. (The first race, however, was cut short because conditions were deemed too dangerous.)
When he invited Mr. Messner to join him in Antarctica, Mr. Lecamp insisted that they run the entire course together. Mr. Messner, an accomplished alpinist who scaled Mont Blanc in 2022 wearing a previous version of the 1858 Geosphere watch, was game.
“I generally see life consisting of possibilities, and this was just another possibility to know my body a bit better,” Mr. Messner said. “It was different from mountaineering. Normally, when I climb, there are a lot of fears and they were totally missing.”
On the day of the race, he was focused on time. “I’m not always wearing a watch while mountaineering, but when running a marathon, it makes much more sense because time counts,” Mr. Messner said. “The great thing about the watch I wore in Antarctica was the lightness. I don’t know of another automatic watch that’s this light.”