The Hamilton Khaki X-Mach ($1700) takes aviation watches to another level with it’s ability to measure the Mach speed of your aircraft. Simply input your calculated air speed plus your altitude, then the X-Mach will display just how fast you’re going relative to the speed of sound, or Mach 1.

Ok, you’re probably never going to need that unless you happen to be a pilot but it’s still cool to say you can! Movement is from the Valjoux 7750 and the watch is encased in a PVD-treated stainless steel with a sapphire crystal. Choose between black or brown leather straps or the more durable rubber. The X-Mach is water resistant up to 100 meters.