For example, a watch with a 3 ATM rating is water-resistant up to 30 meters (or 98 feet), while a watch with a 10 ATM rating is water-resistant up to 100 meters (or 328 feet).
It's important to note that the ATM rating is not a guarantee that the watch is waterproof, and it's always best to avoid submerging your watch in water for an extended period of time. Additionally, the water resistance of a watch can decrease over time, so it's important to have your watch serviced regularly to ensure that it remains water-resistant.