Marathon Navigator (NAV) watches were originally developed in partnership with Kelly Air Force Base in 1986. The NAV Series consists of timepieces engineered to stand up to the rigours of high-altitude flight — and even possible ejection from a fighter aircraft. Featuring an iconic asymmetrical case design available in both 316L stainless steel and high-impact composite fibreshell for ultra-light durability, each watch is equipped with a sapphire crystal tolerant of rapid changes in air pressure; a continuously glowing dial; and a bi-directional bezel with the ability to track a second time zone.