Your smartwatch says it's water resistant to 50 metres. Does that mean you can dive 50 metres deep? Can you shower with it? What about surfing or water skiing? The world of water resistance ratings is surprisingly confusing, and misunderstanding them can lead to expensive water damage.

This guide demystifies the various water resistance standards so you can confidently use your smartwatch around water—without accidentally destroying it.

Understanding ATM Ratings

ATM stands for "atmospheres" and describes static water pressure. One ATM equals the air pressure at sea level. Each additional ATM represents approximately 10 metres of water depth in static conditions.

Here's what the common ratings mean:

  • 1 ATM / 10m: Splash resistant only. Avoid immersion.
  • 3 ATM / 30m: Rain and brief splashing. Not suitable for swimming.
  • 5 ATM / 50m: Swimming and showering generally safe. Most common smartwatch rating.
  • 10 ATM / 100m: Swimming, snorkelling, and water sports. Premium fitness watches.
  • 20 ATM / 200m: Recreational scuba diving. Found on specialised dive watches.

Critical Misconception

A 50-metre rating does NOT mean you can dive 50 metres. The rating measures static pressure resistance in laboratory conditions. Dynamic activities—like swimming strokes or jumping into water—create significantly higher momentary pressures that exceed the equivalent static depth.

Why Depth Ratings Are Misleading

Imagine you're swimming laps at your local pool. You're nowhere near 50 metres deep, but your arm movements create rapid pressure changes against the watch. When you do a flip turn and push off the wall, the momentary force spike can exceed the pressure of being 30+ metres underwater statically.

This is why a 50-metre (5 ATM) rated watch is appropriate for swimming, while a 30-metre (3 ATM) watch should never enter a pool. The ratings account for the dynamic pressures of their intended use case, not literal diving depth.

IP Ratings Explained

Some smartwatches use IP (Ingress Protection) ratings instead of or alongside ATM ratings. IP ratings include two numbers:

  • First digit (0-6): Solid particle protection (dust)
  • Second digit (0-9): Liquid ingress protection

Common smartwatch IP ratings include:

  • IP67: Dust-tight, submersion in 1 metre of water for 30 minutes
  • IP68: Dust-tight, continuous submersion beyond 1 metre (manufacturer specifies depth)
  • IPX7: No dust rating specified, 1-metre submersion for 30 minutes

An IP68 rating with a specified 1.5-metre depth is roughly equivalent to 5 ATM for practical purposes, though the testing methodologies differ.

What You Can Actually Do

5 ATM (50m) Watches - Most Smartwatches

This includes Apple Watch, Samsung Galaxy Watch, Google Pixel Watch, and most fitness trackers. Safe activities include:

  • Swimming in pools (surface swimming)
  • Showering (with caveats—see below)
  • Rain and hand washing
  • Snorkelling at surface level

Avoid these activities:

  • Water skiing or jet skiing (high-velocity water impact)
  • Scuba diving
  • Jumping from diving boards (impact pressure)
  • Hot tubs and saunas (extreme temperatures degrade seals)

The Hot Water Issue

Most manufacturers advise against showering with your smartwatch, even when ratings suggest it's safe. Hot water and soap can degrade the rubber gaskets that maintain water resistance. Additionally, temperature changes cause materials to expand and contract, potentially allowing moisture ingress. Lukewarm showers are generally fine; hot, steamy showers pose more risk.

10 ATM (100m) Watches - Garmin Fenix, Outdoor Watches

These premium fitness watches add confidence for:

  • Open water swimming
  • Water skiing and wakeboarding
  • Snorkelling at depth
  • Cliff jumping (within reason)

Still avoid:

  • Scuba diving below recreational limits
  • High-pressure water jets
  • Extended sauna exposure

Saltwater Considerations

Ocean swimming requires additional care. Saltwater is more corrosive than fresh water and can accelerate seal degradation. After ocean swimming:

  • Rinse your watch thoroughly with fresh water
  • Dry the watch and band completely
  • Pay special attention to cleaning around buttons and sensors
  • Never press buttons while the watch is submerged (creates pressure points)

The salt itself isn't immediately damaging, but salt crystals left to dry on your watch can work into seams and create wear points over time.

When Water Resistance Fails

Water resistance isn't permanent. Over time, the rubber gaskets and seals that protect your watch degrade. Factors that accelerate this degradation include:

  • Heat exposure: Rubber gaskets become brittle with repeated temperature cycling
  • Impacts: Dropping your watch can compromise seals even without visible damage
  • Chemical exposure: Chlorine, sunscreen, soaps, and perfumes can degrade materials
  • Age: Even without abuse, gaskets naturally degrade after 2-3 years

Warning Signs

If you notice fog or condensation forming inside your watch screen, moisture has already entered. Immediately power off the device and seek professional service. Continued use with internal moisture will cause corrosion and permanent damage.

Maintaining Water Resistance

To maximise your watch's water resistance longevity:

  • Rinse with fresh water after exposure to salt, chlorine, or sweat
  • Never press buttons while the watch is wet
  • Avoid sudden temperature changes (jumping from a hot tub into a cold pool)
  • Apply sunscreen before putting on your watch, letting it absorb fully
  • Keep charging contacts clean and dry
  • Consider professional seal inspection every 2-3 years for premium watches

Key Takeaway: Practical Water Resistance Guide

  • 5 ATM (50m): Pool swimming, rain, brief showers—yes. Hot tubs, diving, water skiing—no.
  • 10 ATM (100m): All surface water sports including open water swimming and snorkelling.
  • Rinse after saltwater or chlorine exposure
  • Avoid hot water and steam
  • Don't expect ratings to last forever—seals degrade with age and use

Warranty Considerations

Most smartwatch warranties explicitly exclude water damage, even on water-resistant devices. If you damage your watch through water exposure, proving that you stayed within the rated specifications is nearly impossible. Manufacturers assume misuse or seal degradation in most water damage claims.

This isn't a reason to avoid water—it's a reason to use appropriate caution. Treat water resistance as a safety margin rather than a challenge to push.

For most users with 5 ATM watches, normal pool swimming and occasional rain exposure will never cause problems. Just remember that your smartwatch is ultimately an electronic device, and treating it with reasonable care will ensure years of reliable service around water.