Tudor Black Bay P01 42mm satin-f inish steel case, brown leather, rubber and steel hybrid strap

Based on a 1967 prototype watch for US Navy divers codenamed the “Commando” which was not accepted into service, Tudor has now raided its archives to expand its ultra-successful Black Bay range with this unusual tool watch based upon that blueprint. Uniquely built for the world aquatic where underwater and surface exploration merge, the hefty P01 is rated waterproof to 200m while its bi-directional bezel is marked off in hours for navigating sailors to time their chart courses. The crown being set lower at 4 o’clock offers it protection from the rough stuff under or above the waves, but the watch’s most notable feature is the hinged end link system on the leather-rubber strap which locks into the bezel’s teeth to prevent accidental movement from bashes and knocks. If extreme water sports are your thing, this is your watch. BF £2,830; tudorwatch.com