Favre-Leuba made a triumphant return to Baselworld last year when it unveiled the Raider Bivouac 9000, the first mechanical wristwatch capable of measuring altitudes of up to 9,000 meters above sea level. This year, it unveiled the Raider Bathy 120 MemoDepth, the only mechanical wristwatch capable of measuring and displaying depth to 120 meters.

The Bathy is now revived as a retro-futuristic tool watch

Once a name to be reckoned with in the Swiss watch industry, Favre-Leuba had little to show to its name in the last two decades till it was revived under CEO Thomas Morf as a retro-futuristic tool watch brand. The new Raider Bathy 120 MemoDepth further emphasizes this new brand DNA.

Water permeates to the membrane via apertures on the caseback

The hefty 48 mm titanium case houses a special membrane, which compresses with the changing depth and water pressure. This membrane is hermetically sealed from the movement, to ensure that even if the diver dives below 120 meters, there is no damage to the watch.

The 1968 original was the first diver with a depth gauge

This year marks the 50th anniversary of Favre-Leuba’s legendary Bathy diver. Launched in 1968, this legendary tool watch was the first to incorporate a mechanical depth gauge. While the original could measure depths up to 50 meters, the 2018 can measure depths up to 120 meters. The watch is also water-resistant to 200 meters, like all modern dive watches.

So how does the depth gauge work? The caseback features an aperture in the form of the brand logo, through which water enters the watch and makes contact with a specially designed membrane. A mechanical contact sensor reacts to the variation of the water pressure experienced by the membrane and that is then relayed on to the dial via blue dive hands on the dial.

A cutaway figure shows the membrane in the movement

The central blue hand displays the current dive depth on a scale placed in ring around the edge of the dial. The first 30 meters on the scale has finer markings, while thereon it is marked with 10 meter intervals. Two red indicators between 3 and 6 m and between 9 and 12 m highlight the depth where decompression stops may be necessary.

Also new in the resurrected Bathy is a mechanical depth memory (MemoDepth), which stores the maximum depth reached during a dive. The depth gauge at 3 o’clock displays this max depth value until it is reset via the screw-in pusher at 4 o’clock – a feature that typically appears on professional dive watches.  

An exploded view of the FL321 movement

The watch is powered by the self-winding FL321 movement, which is based on Eterna’s EMC 3903M movement, completely reengineered for use in this watch. After the Bivouac 9000, this is another testament to the brand’s engineering capabilities.