— the smartwatch feature for underwater activities measures depth using hydrostatic pressure and displays current meters, maximum depth for the session, and dive duration in real time. Some models add alerts for rapid ascent and save the dive profile for later analysis. Compared to standard "water resistance for swimming," the depth gauge is fundamentally more useful: it not only "isn't afraid of water," but provides figures for controlling safety and progress, whereas an altimeter in the air and a pedometer on land do not solve these tasks. For accurate operation, a watch with an appropriate WR class and a separate dive mode is required, otherwise, the readings will be inaccurate. Typical scenarios are snorkeling with a depth of 3–8 meters, breath-hold training in the quarry, recreational dives up to permissible depths. The depth gauge helps select a comfortable level, mark "ceiling" depth, and keep session logs without bulky equipment.
