Why is that critical? If a unidirectional bezel is knocked and accidentally moved with a dive, it might only Show a longer underwater time. Meaning the wearer will overestimate as opposed to undervalue immersion time, As well as in scenarios that involve decompression stops, This may be a make-it-or-crack-it aspect https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/