Favre-Leuba Watch Raider Bivouac 9000 00.10105.06.46.31. Perseverance, incredible willpower, and courage helped Japanese mountaineer Junko Tabei become the first woman to reach the summit of Mount Everest on May 16, 1975. On her wrist, the worlds first mechanical wristwatch capable of measuring air pressure and altitudes of up to 3000 m above sea level via an aneroid barometer. Favre Leuba developed this revolutionary instrument watch 12 years earlier. Christened Bivouac, the piece set new standards in the art of watchmaking and quickly became an essential companion for mountain climbers, pilots, explorers, and outstanding pioneers.