List of NATO execises.
https://shape.nato.int/exercises/allied-national-exercises
That is a wrist altimeter not a watch.
Show zero feet altitude.
MA 2-30 Wrist Altimeter Indicator
This professional civilian model was used by USAF pararescuemen for High Altitude Low Opening (HALO) parachute jumps. (U.S. Air Force photo)
https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/196865/ma-2-30-wrist-altimeter-indicator/