Why is the fact critical? If a unidirectional bezel is knocked and accidentally moved over a dive, it could only Exhibit an extended underwater time. That means the wearer will overestimate in lieu of underestimate immersion time, and in cases that need decompression stops, this can be a make-it-or-break-it issue https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/