Why is that important? If a unidirectional bezel is knocked and unintentionally moved on the dive, it may only Show an extended underwater time. Which means the wearer will overestimate as an alternative to undervalue immersion time, and in predicaments that call for decompression stops, this can be a make-it-or-split-it https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/