Smartwatch Water Resistance Rating — IP68 vs. 5ATM Explained

You see “IP68” on a smartwatch listing and assume it means the watch can handle a swim. That’s the exact assumption that leads to water-damaged devices and voided warranties. The labels on product pages — IP67, IP68, 5ATM, 3ATM — each mean something specific, and the gap between what they sound like and what they actually protect against is wider than most buyers realize. This guide breaks down every rating, explains what the tests behind them actually measure, and gives you a clear framework for matching a smartwatch’s water resistance to the activities you actually do.

The Two Rating Systems You Need to Know: IP vs ATM

There are two completely separate systems used to rate water resistance on smartwatches, and they measure different things. Seeing one on a spec sheet without the other only tells half the story.

IP — Ingress Protection is the system developed by the International Electrotechnical Commission (IEC). The “IP” in IP68 stands for ingress protection, and the rating uses two digits: the first covers solid particle protection (dust, debris), and the second covers liquid protection. A rating of IP68 means the highest dust protection (6) and a high level of water immersion protection (8). When you see IPX8, the X simply means dust resistance wasn’t tested — common on wearables where the manufacturer focused only on liquid protection.

ATM — Atmosphere is the system governed by the International Organization for Standardization (ISO). It measures how much water pressure a device can withstand, expressed as equivalent atmospheric pressure. One ATM equals roughly ten meters of water depth, so 5ATM equals 50 meters, and 10ATM equals 100 meters. These aren’t dive depth guarantees — they’re pressure thresholds measured under controlled conditions.

A watch can carry an IP rating, an ATM rating, both, or neither. Having both gives you the most complete picture. IP tells you what the device survived in a lab immersion test. ATM tells you how much pressure the seals can theoretically handle. Neither tells you the whole story on its own — which is exactly why the marketing around these labels causes so much confusion.

Every Water Resistance Rating Explained: From 3ATM to 10ATM

Here’s how each rating tier translates into what you can actually do while wearing your watch.

3ATM (30 Meters)

This is the entry point for water resistance on reputable smartwatches, and it’s a modest one. Sweat, rain, and hand washing are fine. Brief splashes are fine. Swimming — even a quick dip — is not. Don’t let the “30 meters” figure mislead you; that’s a static pressure test, not a real-world depth guarantee.

IP67

IP67 protects against immersion between 15cm and one meter deep for up to 30 minutes in still, fresh water. It’s genuinely useful for accidental submersion — dropping your watch in a sink, getting caught in heavy rain — but it’s not a swimming rating. The test conditions don’t come close to replicating what happens in a pool.

IP68

IP68 raises the immersion depth to at least 1.5 meters for up to 30 minutes, again in still, fresh water. The Samsung Galaxy Watch 7 carries this rating, and it’s fine for splashes, showers, and brief accidental dunks. But read the next section before you take it to the pool — IP68 is where the biggest misconceptions live. The Samsung Galaxy Watch 7 is a solid everyday smartwatch, but its IP68 rating alone doesn’t make it a swimming companion.

5ATM (50 Meters)

This is the minimum rating for swimming. 5ATM and 50 meters are the same thing — always. At this tier, the watch has been tested against meaningful pressure, making it suitable for surface swimming, pool laps, and snorkeling. Even so, Apple recommends no more than 30 minutes in water for the Apple Watch Series 9, which carries a 5ATM rating. That manufacturer guideline matters — the rating is a benchmark, not a blank check.

10ATM (100 Meters)

10ATM and 100 meters are the same rating. At this level, you’re looking at watches built for serious water exposure — surfing, jet-skiing, open water swimming, and recreational diving. The Apple Watch Ultra 2 sits at this tier and carries EN13319 certification, making it a verified diving instrument rated to 40 meters. It’s the benchmark for premium water resistance in the smartwatch category. If you want that level of protection, the Apple Watch Ultra 2 is the most thoroughly certified option available.

Here’s the full picture in one view:

The IP68 Myth: Why “Waterproof” Does Not Mean What You Think

Here’s the thing about IP68 — the test that earns a watch that label has almost nothing in common with the conditions of an actual swim. The IEC test is conducted in still, fresh water at a controlled temperature between 18°C and 25°C. There is no specification for water pressure from movement, no requirement to test against a faucet jet, no chlorine, no saltwater, and no simulation of what happens when you push your hand through water at speed.

That means a watch can pass IP68 and still fail under a running tap, in a hot shower, or during a vigorous freestyle stroke — because all three generate dynamic pressure that the test never simulates. The word “waterproof” doesn’t appear on compliant product labeling for good reason: the Federal Trade Commission prohibits its use because no consumer device can genuinely claim to be waterproof. Brands that imply otherwise are pushing the limits of accurate marketing.

For swimming, you need 5ATM or higher — not just IP68. The ATM system specifically tests pressure resistance, which is what actually matters when your arm is moving through water. IP68 tests immersion in a bucket. Those are not the same thing.

To be clear about what IP68 is good for: splashes, brief accidental submersion, wearing your watch in a light shower. It’s a useful rating for everyday life. It just isn’t a swimming rating, regardless of how it’s described in marketing copy. If you’re shopping with water activities in mind, our smartwatch buying guide covers this alongside the other specs worth scrutinizing before you commit.

Static Ratings vs Real-World Pressure: Why Your Rating Isn’t the Whole Story

Every water resistance rating is assigned under controlled, stationary conditions. The watch sits motionless at a set depth, in still water, at a temperature between 18°C and 25°C. That’s the test. That’s what the number on the box reflects.

The moment you move through water, the physics change. A freestyle swimming stroke, a diving entry, or a wave impact generates pressure spikes that can significantly exceed what a stationary depth test measures. A watch rated to 50 meters in a lab can encounter equivalent or greater pressure at a fraction of that depth when the wearer is actually moving. Water sports like surfing or jet-skiing compound this further — the force of water hitting a watch at speed bears no resemblance to the test environment.

This is the engineering reality behind Apple’s 30-minute recommendation for the Apple Watch Series 9. The 5ATM rating is a controlled-condition benchmark. The manufacturer’s guideline acknowledges that real-world use introduces variables the rating doesn’t account for. That’s not a flaw in the watch — it’s an honest acknowledgment of what a water resistance rating actually is.

Thermal expansion adds another layer. Gaskets and seals behave differently at elevated temperatures. Hot showers and saunas create conditions that a standard immersion test never replicates, which is why even high-rated watches can be compromised by heat exposure that seems minor on the surface.

Water Resistance Wears Out: How to Protect Your Investment

A smartwatch that passed its water resistance test on the production line is not guaranteed to maintain that rating two years later. Water resistance is a function of physical seals — gaskets around the crystal, case back, and crown — and those seals degrade. Heat, UV exposure, chlorinated pool water, saltwater, soap, and shampoo all accelerate the process. The rating on the box reflects the watch when it was new.

For anyone who regularly swims or showers with their watch, annual inspection by a watchmaker or authorized service center is a reasonable precaution. They can pressure-test the watch and replace gaskets before a failure happens rather than after. It’s the kind of maintenance most owners don’t think about until water damage makes it obvious.

Two habits make a meaningful difference in extending seal life. First, rinse your watch with fresh water after every pool or ocean session. Chlorine and salt don’t just sit on the surface — they work into seals over time and accelerate degradation. Second, avoid hot showers and saunas with your watch on. Thermal expansion of the case and seals under sustained heat can compromise the fit that keeps water out.

This applies even to 5ATM and 10ATM watches. A high rating means the seals were built to a higher standard — it doesn’t make them immune to wear. Treat your watch’s water resistance as something to maintain, not something to take for granted.

Which Rating Do You Actually Need? A Practical Decision Guide

Strip away the technical detail and the decision comes down to your actual use case. Here’s how to match a smartwatch water resistance rating to what you do.

Gym, commute, rain, hand washing: 3ATM or IP67 covers you. You’re not submerging the watch intentionally, and these ratings handle incidental moisture without issue.

Showering regularly with your watch on: Aim for 5ATM minimum. IP68 alone is not sufficient — the pressure from a shower head, especially a high-flow one, can exceed what an IP68 test simulates.

Pool laps or casual open water swimming: 5ATM is the floor. For regular swimmers, a watch combining 5ATM with IPX8 is preferable, and ISO 22810 certification — the independent standard for water-resistant watches — gives you more confidence than a self-reported ATM claim from the brand alone. The Fitbit Charge 6 sits in this tier and is a widely used option for pool tracking.

Surfing, jet-skiing, or vigorous water sports: 10ATM minimum. The dynamic pressure from water sports can exceed what a 5ATM watch is built to handle.

Recreational scuba diving: 10ATM plus EN13319 certification. EN13319 is the independent standard for diving instruments — it’s a different and more demanding certification than ISO 22810. The Apple Watch Ultra 2 is the clearest example here, certified for dives to 40 meters and built to handle the pressure conditions of actual diving. For serious swimmers and divers who want a capable step down in price, the Garmin Forerunner 55 is a 5ATM-rated option built for active use and regular pool sessions.

One final point: always read the manufacturer’s specific guidelines alongside the rating. Brands sometimes impose tighter real-world recommendations than the rating technically allows — and those guidelines exist for a reason. The rating is a floor, not a ceiling, and the brand’s own advice is worth taking seriously.

If you’re still working out which type of smartwatch fits your lifestyle overall, choosing the right smartwatch covers the full picture beyond water resistance.

Frequently Asked Questions

What does IP68 mean on a smartwatch?

IP68 is an ingress protection rating issued by the International Electrotechnical Commission. The “6” indicates full dust protection; the “8” means the device can withstand immersion in still, fresh water to at least 1.5 meters for up to 30 minutes. It does not account for pressure from movement, hot water, chlorine, or saltwater.

Can I swim with an IP68 smartwatch?

Not reliably. The IP68 test uses still, fresh water at room temperature with no pressure specification — conditions that bear little resemblance to actual swimming. For lap swimming or open water, a smartwatch water resistance rating of 5ATM or higher is the appropriate minimum. IP68 is suitable for showers and brief accidental submersion, not pool sessions.

What is the difference between IP67 and IP68?

IP67 protects against immersion to one meter for up to 30 minutes. IP68 extends that to at least 1.5 meters for the same or longer duration, as specified by the manufacturer. Both are tested in still, fresh water. Neither is a swimming rating — that requires 5ATM or higher, which tests pressure resistance directly.

Is 5ATM enough for swimming?

Yes — 5ATM is the minimum smartwatch water resistance rating recommended for surface swimming and pool laps. It’s worth noting that Apple limits Apple Watch Series 9 (5ATM) to 30 minutes in water. For open water or vigorous swimming, a watch combining 5ATM with IPX8 and ISO 22810 certification offers stronger real-world confidence. You can find more options in our roundup of the best smartwatches for men.

Does water resistance wear off over time?

Yes. Gaskets around the crystal, case back, and crown degrade with heat, chemical exposure, and physical wear. A watch that was swim-safe when purchased may not maintain that rating after a year or two of regular use. Rinse with fresh water after pool or ocean use, avoid hot showers, and have the seals inspected annually if you swim regularly.

What does the “X” mean in IPX8?

The X replaces the first digit — the dust protection rating — meaning dust resistance simply wasn’t tested. IPX8 certifies water resistance only. It’s common on wearables where manufacturers chose to test water ingress without going through the dust certification process. Water protection is the same as IP68; dust protection is unknown.

What rating do I need for scuba diving with a smartwatch?

10ATM is the minimum, but the rating alone isn’t enough. For a device to function as a legitimate dive instrument, EN13319 certification is required — that’s the independent standard for diving equipment. The Apple Watch Ultra 2 is the most prominent smartwatch meeting both criteria, rated for dives to 40 meters. For more on how smartwatches compare to fitness trackers for active use, that guide covers the key differences.

The single most important thing to take from this guide: IP68 is not a swimming rating, regardless of how it’s marketed. If your watch only carries an IP68 label, treat it as splash and shower protection — nothing more. For swimming, the minimum is 5ATM, and for anything involving water sports or diving, you need 10ATM with independent certification to back it up. Water resistance also isn’t permanent — the seals that make it work wear down, and the habits you build around rinsing and heat avoidance directly affect how long that protection lasts. Know your rating, know its limits, and you’ll never be caught out by a label that sounded more reassuring than it actually was.