Water resistance of watches: what do ATMs mean?
Whether you are a lover of fine watches or simply curious, the question of water resistance is crucial when you wear a watch on a daily basis.
But what do the ATM markings on your watch really mean? Can you actually swim with a 5 ATM water-resistant watch? Can you wear it while washing your hands or in the shower? This comprehensive article explains everything you need to know about ATM and watch water resistance, mistakes to avoid, the best-performing models, and best practices.
🧭 What are ATMs on a watch?
The acronym ATM stands for "atmosphere", a unit of pressure measurement. In watchmaking, it is used to assess the water resistance level of a watch.
- 1 ATM = 10 meters of theoretical resistance underwater
- Warning: these meters do not correspond to the actual diving depth, but to a pressure simulated in the laboratory.
Example :
- 3 ATM = 30 meters ➝ Splash resistant (hand washing only)
- 10 ATM = 100 meters ➝ Swimming and light snorkeling
- 20 ATM = 200 meters ➝ Amateur diving
- 30 ATM ➝ Professional Diving
🧼 Can you wash your hands or take a shower with your watch?
This is a very common question. Here are the clear answers depending on the ATM level:
Waterproofing | Handwashing | Shower | Pool | Diving |
3 ATM | ✅ Yes | ❌ No | ❌ No | ❌ No |
5 ATM | ✅ Yes | ❌ No | ❌ No | ❌ No |
10 ATM | ✅ Yes | ⚠️ Caution | ✅ Yes | ❌ No |
20 ATM+ | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes (depending on usage) |
👉 Soap, shampoo and hot water are very aggressive on the seals : even at 10 ATM, it is advisable to avoid wearing your watch in the shower, unless it is actually designed for it.
⚠️ What are the risks if we don't respect ATMs?
Failure to comply with sealing instructions can lead to damage that is sometimes irreversible :
- Condensation under the glass
- Corrosion of the movement
- Oxidation of the hands or dial
- Loss of mechanical performance
- Loss of manufacturer's warranty
Even a few drops can cause serious damage. It is therefore crucial to know the actual water resistance rating of your watch before exposing it to water.
🕰️ Which watches have the highest ATM water resistance?
Here are some examples of brand-name watches that we distribute and their water resistance rating:
HERBELIN
- ranges Newport or Cap Camarat ➝ up to 10 ATM, or even 20 (Cap Camarat Automatic Diver 1745N14CMD) or 30 ATM (Newport Automatic Diver 1774BL15C)
- Perfect for everyday use with occasional swimming
FRÉDÉRIQUE CONSTANT
- Classic models ➝ 3 to 5 ATM
- Sport models like the Highlife ➝ up to 10 ATM
BAUME & MERCIER
- Riviera Collection ➝ 10 ATM
- Stylish and robust models, perfect for both city life and leisure activities
ALPINA
- Specialist in sports watches ➝ up to 30 ATM for the Seastrong Diver
- Ideal for diving, swimming, and water sports
PANERAI
- Submersible Models ➝ 30 to 50 ATM
- Designed for professional diving, with an ultra-robust architecture
TUDOR
- Black Bay range ➝ 20 to 30 ATM
- High-performance diving suits with vintage style
ROLEX
- Submariner ➝ 30 ATM
- Sea-Dweller ➝ 1220 meters deep (122 ATM!)
- Deepsea ➝ 3900 meters deep (390 ATM)
🛠️ Our watchmaking workshop checks and maintains the water resistance of your watches
The seal is not permanent : the seals age, dry out, or wear out over time. That's why we recommend:
- ✅ A check-up every 2 years, even without any apparent problems
- ✅ A systematic water resistance test after each battery change (for quartz watches)
Our certified watchmaking workshop offers:
- Pressure test
- Seal replacement
- Complete review
- Restoration of antique watches
🔧 We also provide official after-sales service for the brands Michel Herbelin, Frédérique Constant, Baume & Mercier, Alpina, Panerai, Tudor, and Rolex. Trust our team to preserve the precision and integrity of your timepieces.
📌 In summary: understanding ATMs is key to better protecting your watch
- ATMs are not an actual depth, but a theoretical pressure.
- Don't rely solely on the numbers: 30 meters doesn't mean you can dive to 30 meters!
- Avoid hot water, soap, steam, and thermal shock.
Have the seals checked regularly in a professional workshop.
❓ Quick FAQ – Water Resistance and ATM Rating of Watches
Which watch can I wear in the shower?
Only models designed for: 20 ATM minimum, but even then, be careful of chemicals.
What should you do if condensation appears under the crystal?
Remove the watch immediately and consult our workshop. A quick response can prevent serious internal damage.
Can I swim with a 10 ATM watch?
Yes, swimming is allowed, but avoid diving or violent jumps into the water.
How long does a watch's water resistance last?
It can vary from 12 to 36 months, depending on usage. Regular checks are recommended.
