Why is the fact that important? If a unidirectional bezel is knocked and unintentionally moved on the dive, it may only Exhibit an extended underwater time. Meaning the wearer will overestimate rather than underestimate immersion time, As well as in cases that require decompression stops, This may be a make-it-or-break-it https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/