Why is the fact significant? If a unidirectional bezel is knocked and unintentionally moved on a dive, it could only Show a longer underwater time. Which means the wearer will overestimate rather than underestimate immersion time, and in scenarios that call for decompression stops, This may be a make-it-or-split-it variable https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/