One of the common questions asked in a diver’s community is if a dive watch needs to have a specific depth requirement. Given the different types of diving practices and the complexities of each category, dive watches technically have specific depth ratings to prevent damages to the watch.
The water-resistance of diving watches are measured in ATM or atmospheres, which is the unit of measurement used to determine the level of water pressure a watch can withhold. Therefore, a higher ATM means a watch can withhold more water pressure and vice-versa.
Dive watches’ depth ratings and ATM are interrelated, together with the concept of ATA or Absolute Pressure. However, to avoid confusion and misunderstanding, it is vital to understand each term.
The main idea is not to associate the watch’s rating to the depth you can reach when diving. As an example, a watch with 30 meters of water resistance is not equal to 30 meters depth of diving underwater. The rating only means that it has been tested, in a laboratory setting, at the same water pressure once.
Here is a quick sum-up:
- Watches with 3 ATM (30 meters/100 feet) are suitable for everyday use and can tolerate splashes but not recommended for swimming and diving.
- Watches with 5 ATM (50 meters/165 feet) can be used daily, including bathing but not when swimming.
- Watches with 10 ATM (100 meters/330 feet) are allowed for swimming and snorkeling but not for any diving.
- Watches with 20 ATM (200 meters/660 feet) are perfect for any water sports activities, such as scuba or skin diving.
- Watches with a range of 20 to 50 ATM (200-500 meters) is suitable when doing high impact water sports, as well as scuba and saturation diving.
- Watches with 100 ATM (1000 meters) are recommended for extreme types of diving such as wreck, rebreather, and altitude diving.