Racing Watches track time accurately during motor races. What these watches require are: a high-contrast dial to read time even at high speeds; a chronograph; a tachymeter bezel enables speed calculations. In the past also an angled case orientation (to be read without taking hands off the wheel) and rally-strap style (breathable leathers or rubber) were necessary.
Pilot’s Watches started off because aviators needed to read time while controlling aircrafts. Cartier produced the Cartier Santos in 1904, considered the first pilot’s watch. Requirements of these timepieces are: large and luminous dials to tell time in any meteorological condition; anti-magnetic case as to avoid the timepiece to run faster; oversized winding crown because pilots would wear gloves so to facilitate rotating the bezel; extra bezel markings to make complex calculations such as fuel burn estimation; dual time or GMT functions to display two time zones.
The scope of Military Watches is to synch war attacks. Also known as “Trench Watches”, they were named after the long and narrow ditches in which soldiers would gather waiting for orders. Must-have features were: legible and luminous dials to read time at any condition; A hacking second hand to sync with another wristwatch; Be glare-proof to avoid being seen from the enemy; and last but not least have the ability to resist to dust and scratches, by utilizing sapphire glass.