In collaboration with Kenzo Dijkstra - Watches Expert
Buying a new watch is always a fun adventure. You have to determine what kind of requirements you want your watch to have. For instance: do you want an automatic or quartz movement, do you want a mineral, plexi, or sapphire glass, do you want it to be able to withstand a refreshing dive in the swimming pool or an adventurous scuba dive into the depths of the ocean? This article explains what water resistant watches really are, so you know what you really buying.
Gradations of water resistance
The water resistance is usually marked at the back of the watch. When the water resistance of a watch is fairly high, like on a diver's watch, it is common to also state the water resistance on the dial. There are several terms on how the water resistance of a watch is indicated: BAR, ATM, FT, M.
- ATM: ATM stands for atmosphere. 1 atmosphere is equal to 10 meters in stagnant water.
- BAR: A BAR (Bar of meters) is just another way to define the atmosphere, which means it's basically the same.
- FT: is the water resistance rated in feets in stagnant water.
- M: is the water resistance rated in meters in stagnant water.
Water resistant watches are generally graded 3, 5, 10, 20 or 30 ATM/BAR. This respectively means 30, 50, 100, 200 and 300 meters of water resistance. But you shouldn't take it that literally. The tests are done in a water resistance testers. The watch is put in a tester. The tester slowly raises the pressure, in stagnant water, until it reaches the pre-set water resistance. The tester then gives a go or no go to the tested watch if the watch can resist certain water pressure.
Non-rated watches
If your watch doesn’t say it’s water resistant, treat it like it is made of paper. Water is terrible for these watches and can damage it completely.
3 ATM/BAR
These watches can withstand a pressure of 3 ATM, which equals 30 meters underwater in stagnant water. What it actually means is that the watch is protected from raindrops and water splashes. It does not really mean that your watch can withstand 30 meters underwater.
5 ATM/BAR
These watches can withstand a pressure of 5 ATM, which equals 50 meters underwater in stagnant water. The watch can be worn while swimming. The watch is water resistant enough to be worn under the shower. However, it is not safe to dive with this watch. When you plan to be in the water for a long period of time, you should take the watch off as a precaution.
10 ATM/BAR
These watches can withstand a pressure of 10 ATM, which equals 100 meters underwater in stagnant water. The watch can be worn while swimming. These watches are usable for water sports like snorkeling. Don’t use these watches for surfing or diving into the water because the watch is not build to withstand sudden pressure changes that can occur while doing this.
20 ATM/BAR
These watches can withstand a pressure of 20 ATM, which equals 200 meters underwater in stagnant water. It is perfectly possible to use these 20 ATM/BAR rated watches for a recreational diving.
30 ATM/BAR
These watches are suitable for about anything, they can withstand high pressures with sudden pressure changes. These watches are built to last, they are able to survive the worst of the worst and still protect itself.
And remember, whatever the watch you buy is vintage or you don’t know the service history. Ask one of our auctioneers for help. In our weekly watches auctions, you can find all kinds of watches: not-rated or water resistant.