How to Read and Understand Water Resistance Ratings for Watches
Water resistance ratings vary between brands and models, typically expressed in meters (m), bars (bar), or atmospheres (atm or ata). Although scientific measurements differentiate between atm and ata, for standard diving at sea level, atm and ata can be treated the same (differences appear mainly in high-altitude diving). Pressure Equivalents: 1 bar ≈ 0.987 atm…