The Raider Bivouac 9000 by Favre-Leuba is a practical watch designed for mountaineers, incorporating an altimeter which shows air pressure and your altitude from 0 to 9,000m. It is a large watch in titanium, 48 mm in diameter and 18.7 mm in thickness. It incorporates an aneroid chamber whose movements power the altimeter function.
Clear dial indications
The display is organised in a practical way. The red central hand indicates height in metres on the rotating bezel, which is marked from 0 to 30, that is from 0 to 3,000 metres. As you go higher, it continues to wind around the dial for up to 3 times. At the same time, the subdial at 3 o’clock shows you the height on a smaller scale and can be used to see whether you are in the range from 0 to 3,000m, or from 3,000 to 6,000, or from 6,000 to 9,000. The subdial also shows the air pressure. The neat feature of the watch is the bidirectional rotating bezel with an anodized aluminium insert. As air pressure is not constant, you need to adjust the watch when you are at a known height so that subsequent readings will be accurate. The dial also has a date window at 6 o’clock and a power reserve indicator at 12 o’clock.
The Raider Bivouac 9000 Is powered by the FL311 movement based on the Eterna EMC 3903M calibre, with specially-designed mechanisms for the altimeter and power reserve indicator. Power reserve is 65 hours. The watch has a solid caseback and a grey leather strap with pin buckle.
30 metres water resistance
The watch is based on a previous model also called the Bivouac, introduced in 1962 and capable of measuring altitudes of up to 3,000 metres. The new version extends the range of altitudes that can be shown. The case has a 3-atmosphere, 30-metre water resistance, achieved by a special covering over the air inlet. It is essential to allow air to penetrate the aneroid chamber, and a micro-perforated water-resistant repelling membrane allows the passage of air but not water or dust.
The Raider Bivouac 9000 costs $7,750, 7500 Swiss francs. It has an interesting function that makes it a rarity in the world of watchmaking. It will be of interest of people who climb in the mountains but also to hang glider and paraglider pilots. There are two other watches providing an altimeter function, the Oris Altimeter Rega Limited Edition (3,950 Swiss francs) and the Breva Génie 02 ($132,000).
Favre-Leuba returned to the market in 2017 after a period of inactivity. Originally a family company, it has recently changed hands several times and in 2011 it was bought by Titan, part of the Tata group and India’s largest watch brand and retailer. More information from the Favre-Leuba website.