Diving watch: what WR 50, 100, 200 and water resistance mean

What WR means: the water resistance rating

WR is the abbreviation for "Water Resistant." Every quality watch features this rating followed by numbers that indicate the level of water pressure the internal movement can withstand.

A common mistake is believing that WR 50 means "waterproof up to 50 meters deep." In reality, the numbers refer to the test pressure (in bar or ATM), not the reachable depth. This distinction is crucial for choosing the right watch for your activities.

The two standards that matter: ISO 22810 and ISO 6425

Testing is established by two different international standards. ISO 22810 concerns "water-resistant" watches designed for daily use and swimming: each piece is tested under static pressure in a laboratory. ISO 6425, on the other hand, concerns true diver's watches: at least 100 meters of resistance, a rotating bezel for dive time, readability in the dark, and more rigorous tests (shocks, salt, condensation). Only the latter can bear the label "Diver's" followed by the depth in meters; this is why a watch with WR 200 but without the "Diver's" label is not a professional diving instrument.

The three main levels of resistance

WR 50 (5 bar / 5 ATM)
The entry-level for casual water use. A WR 50 watch withstands daily life—hand washing, rain, splashes—and, according to charts from major manufacturers like Casio and Citizen, also surface swimming. It is not suitable for diving, snorkeling, or intense water sports: for those, you need at least WR 100.

WR 100 (10 bar / 10 ATM)
The intermediate level, ideal for those who practice recreational water activities. With WR 100, you can swim in a pool, snorkel at the surface, and enjoy light water sports (kayaking, windsurfing). This level is the most popular for sports watches, a good compromise between functionality and aesthetics: it is the category for most of the men's Citizen watches we keep in stock, and you can find them gathered in our selection of diver's and WR 100 watches.

WR 200+ (20 bar / 20 ATM and above)
Handles more intense water sports: diving, water skiing, surfing, and prolonged snorkeling. Most Casio G-Shock watches fall into this range. However, for scuba diving, the number alone is not enough: you need a watch certified to ISO 6425, identifiable by the "Diver's" label (e.g., "Diver's 200m"). Even higher levels (300 meters and above) are reserved for watches designed for technical diving.

The crucial difference: pressure vs. depth

At a depth of 50 meters, the water pressure on your wrist is approximately 5 bar higher than at the surface. Yet a WR 50 watch is not meant to be taken to 50 meters.

The reason is that the ISO 22810 test takes place in a laboratory, with the watch stationary, in water at a controlled temperature, and on a brand-new piece. In real life, there are temperature variations, shocks, aging gaskets, and crowns that may not be screwed down: all conditions that reduce the margin of safety. Therefore, the rating should be read as a class of usage, not as a maximum depth.

Diver's watches certified to ISO 6425 are instead tested with overpressure, thermal shock, and prolonged immersion, which is why they are the only ones suitable for scuba diving.

How to choose the right watch for you

Daily life without water sports? WR 50 is sufficient. Doing dishes, cold showers, rain—no problem. This category includes almost all women's steel watches and models with leather straps, which should be kept away from submersion anyway: it is the leather that cannot handle water, not the case.

A swimmer or fan of light water sports? Go with WR 100. It is the level that offers complete protection for recreational use, and the design remains elegant and versatile. If you are looking for something that handles shocks as well as water, look at the Casio G-Shock models: we explain how to choose a model in our G-Shock guide.

A serious SCUBA diver? Choose a watch with the "Diver's" label and ISO 6425 certification. Brands like Citizen and Bulova offer excellent models in this category: you can find men's Bulova watches in our catalog, and for details on how Citizen's light charging works, there is a dedicated guide to Eco-Drive. To compare WR with other selection criteria—movement, case, strap—check out the guide on how to choose a watch.

If you don't want to wait for a restock, our last pieces page shows in real-time only the watches currently in stock: for several Bulova and Citizen items, only one piece remains, and there you can see them all together with their declared water resistance in the specifications.

Warranty, battery replacement, and gasket checks are explained on the men's watches: frequently asked questions page. Not sure about your watch's WR level or the one you are about to buy? Write to us via the contact page: we will tell you exactly what it can and cannot handle, before it's too late.

On Pinterest, we collect models and comparisons on our Citizen Eco-Drive Watches and Casio G-Shock Watches boards.

FAQ — Frequently asked questions about water resistance

Q: Can I take a WR 50 watch into the shower?
A: Yes, the cold water spray of a shower is safe. Avoid direct jet contact on the dial if possible, and dry it well afterward.

Q: Is WR 100 truly waterproof for the pool?
A: Yes, WR 100 is perfect for swimming in a pool. Just avoid deep dives or pools with powerful water jets, such as wave pools.

Q: What is the difference between WR and ATM?
A: They are synonyms. 1 bar is approximately equal to 1 ATM. WR 50 = 5 bar = 5 ATM.

Q: If a watch says "Water Resistant" without a number, what does it mean?
A: It means basic resistance. Do not submerge. Use it only for accidental splashes.

Q: What do I do if the glass fogs up or water gets inside?
A: Take the watch to a watchmaker as soon as possible, without waiting for the fogging to "go away on its own": condensation under the glass means the seal has failed and moisture is already in contact with the movement. In the meantime, do not press the buttons and do not turn the crown, as any movement draws more water inside. A quick intervention usually involves drying and new gaskets; if you wait, you risk rust on the movement, making the repair prohibitively expensive.

Q: Does hot water and a sauna damage a diver's watch?
A: Yes. Gaskets are tested in cold water: heat causes them to expand and lets steam pass through, which then condenses under the glass. No WR level protects against saunas, boiling showers, or hot tubs.

Q: How often should water resistance be checked?
A: Gaskets age: for a watch used in water, it is advisable to have them checked every 2-3 years, and always after a battery replacement, because opening the case back breaks the seal.

Q: Is a WR 200 watch good for scuba diving?
A: Not necessarily. WR 200 indicates the resistance tested according to the ISO 22810 standard, designed for swimming and water sports. For diving, you need a watch certified to ISO 6425, identifiable by the "Diver's" label followed by the depth in meters: it has a bezel for timing dives, indices readable in the dark, and more rigorous leak tests.

Article written by Editorial Staff — Gioielleria Tosti, Cosenza, since 1972. Official distributor of certified Italian jewelry and watches.
Published 2026-08-01 | Updated 2026-10-04