Why is always that crucial? If a unidirectional bezel is knocked and unintentionally moved on the dive, it can only Screen a longer underwater time. Meaning the wearer will overestimate instead of underestimate immersion time, As well as in scenarios that involve decompression stops, this can be a make-it-or-crack-it variable https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/