Light enough to forget it is on your wrist and legible enough to read at a glance in a dark cockpit, the Marathon NAV (reference WW194001BK-0801-KIT) is the purist's Pilot's Navigator: 41mm, no date, a sterile black dial and self-powered tritium illumination.

The Navigator story begins in 1986, when Marathon worked with Kelly Air Force Base to build a timepiece for U.S. Air Force pilots. The requirements were unforgiving: a case that would not weigh the wrist down, a dial that stays readable in any light, and a bezel that earns its place during navigation. Marathon answered with a lightweight composite shell case and a bi-directional 12-hour bezel for following a second time zone. This sterile edition keeps the dial free of government or unit insignia, so nothing competes with the hands and indices. Tritium gas tubes on the hour markers, hands and bezel pip glow around the clock without any light charging and are rated for roughly two decades of service.

Inside is a Swiss ETA F06.115 HeavyDrive quartz movement, chosen to push the hands with extra torque. When a fresh battery is eventually due, the easy-access battery hatch keeps the job simple. On its black nylon strap, this is a pilot's watch that is equally at home on a trail, at a desk or tucked under a jacket cuff.

Marathon NAV WW194001BK-0801-KIT Specifications

• Reference: WW194001BK-0801-KIT
• Case: 41mm black composite shell, 11mm thick
• Movement: Swiss ETA F06.115 HeavyDrive quartz
• Water resistance: 6 ATM
• Crystal: sapphire
• Lume: tritium gas tubes on markers, hands and bezel pip
• Bezel and crown: bi-directional 12-hour bezel, pressure crown
• Dial: sterile black, no date
• Strap: black nylon, 20mm lugs

A featherweight Swiss quartz pilot's watch with a pedigree that started on the flight line.