What is 10 ATM in watches?

Watches and other devices come with water ratings. These water ratings are designed to educate the consumer about the intended use of the watch or the permissible levels of exposure of watch to water and depth pressure. Most smart watches that are available on offer these days come with a water rating. One of the water ratings for a smart watch is 10 ATM.

So, what does the ATM in 10 ATM rated watch or device mean? ATM is an abbreviated form for Atmospheres, a unit used to measure the pressure. In our cases, we use the ATM to measure the depth pressure that a watch can sustain whenever it goes under water. When you wear a watch under water, the watch is exposed to a pressure that depends upon the depth at which you are swimming or the depth at which you dived. 10 ATM watch implies that the watch has been tested at a depth pressure of 100 meters or 330 feet below water. Some people may also write 10 ATM as 10 bars. Bar, is again a unit of pressure. So, you may interchangeably use 10 ATM or 10 bars to denote a watch that can sustain depth pressure of 100 meters below water.

Another way to define the ATM is the normal pressure at sea level. 10 ATM means that the device or the watch can withstand 10 times the normal sea level pressure. The rating of 10 ATM assumes significance as it rates or certifies the watch for swimming, snorkeling or diving up to 100 meters. A watch that has been rated 10 ATM can be worn at the time of showering, snorkeling or swimming. You can even wear the watch for diving. But a 10 ATM watch rating does not mean that you can scuba dive with it. Scuba diving watches come with separate water ratings. They explicitly state DIVE and the number alongside, which refers to the depth to which you may scuba dive without damaging your watch.

ATM ratings on watches are a combination of multiple factors that contribute to overall water rating of the watch. The watch glass, sealing and buttons are considered as factors before rating a watch with an ATM rating.

A natural question would be to know the watches that are rated 10 ATM and hence are good for swimming. The Fitbit Versa 3 smart watch is rated as a 5 ATM device. Apple 6 smart watch is also rated as a 5 ATM watch. This means that the Versa 3 and the Apple 6 watch are rated to sustain a depth pressure of 50 meters or 165 feet. Are they suitable for swimming? Technically, the rating suggests that both -Fitbit Versa 3 and Apple 6 watches should be safe for swimming. But, it is prudent to check with user feedback of Fitbit and Apple owners. Practical experience of watch users provides more significant feedback about swimming readiness of smart watches.

Garmin’s Fenix 5 and higher series smart watches are rated 10 ATM. So, these watches can be used during swimming. Suunto 9 also comes with a 10 ATM rating and is fit for swimming and water sports.