Which smartwatch is best for swimming?

Apple Watch Ultra 4 is the best smartwatch for most swimmers, combining polished pool tracking with serious open-water and day-to-day ability. Choose Garmin Fenix 9 instead for long endurance sessions, Suunto Nautic S for dive-specific capability, or Samsung Galaxy Watch Ultra 2 if you use Android. Your usual swim setting decides it.

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Use these links to find the watch and swim setup that matches your training.

• Swimming smartwatches at a glance
• Best overall - Apple Watch Ultra 4
• Best for endurance - Garmin Fenix 9
• Best for Android - Samsung Galaxy Watch Ultra 2
• Best for diving - Suunto Nautic S
• Best affordable option - Amazfit Active 3 Premium
• Which swimming smartwatch should you choose?
• Frequently asked questions

Swimming smartwatches at a glance

Apple Watch Ultra 4 is the strongest all-round choice, but the water rating, battery emphasis and phone you use create clear reasons to choose another model.

Prices were read at the time of writing.

The deciding factor is whether most of your swimming is structured pool training or long open-water work.

Best overall - Apple Watch Ultra 4

Apple Watch Ultra 4 is the best option for most swimmers who use an iPhone and want one watch for pool sessions, open water, exercise and ordinary daily wear.

Its 100m water rating and 40m dive rating provide the clearest starting point. There is a dive computer, built-in GPS and an Always-On Retina display reaching 3000 nits, which helps when you need to read a split outdoors in hard sunlight rather than shade the screen with your other hand.

• Water and dive rating: 100m / 40m
• Dive computer: Yes
• Claimed everyday battery: Up to 50 hours
• Display: Always-On Retina display, 3000 nits
• Case: Titanium
• Dimensions: 49 x 44 x 12 mm

The case is substantial, so strap choice matters between frequent sessions. A silicone strap is the practical pool option because it does not absorb water and is simple to clean. Nylon can feel softer during long dry workouts, while leather, Milanese and metal options make more sense when the watch returns to commuting or evening wear.

That flexibility is unusually useful on an all-day sports watch: Apple Watch Ultra 4 straps are available in silicone, nylon, leather, Milanese and metal. You can therefore keep one water-friendly strap in your swim bag and another for the rest of the week instead of compromising with one band everywhere.

The claimed everyday battery is not an open-water GPS figure. It should not be read as a promise that the watch will record a continuous swim for that entire period. Even so, the combination of swimming, diving and everyday smartwatch ability gives Apple the top position for mixed use.

Best for endurance - Garmin Fenix 9

Garmin Fenix 9 is the better choice when long open-water sessions and wider multisport endurance training matter more than Apple’s pool-to-everyday polish.

The 10 ATM rating, built-in GPS and claimed everyday battery of up to 29 days make its priorities clear. It is built for athletes who may swim as one part of a longer training week involving running, cycling, navigation and recovery tracking.

• Water rating: 10 ATM
• Claimed everyday battery: Up to 29 days
• Display: AMOLED
• Case: Fibre-reinforced polymer
• Available case sizes: 43 / 47 / 51 mm

Those case choices are important on the wrist. The smaller version is the sensible place to start if bulky watches interfere with your stroke, while the larger versions suit swimmers who prioritise a more glanceable screen and broader endurance use.

At the time of writing, the Fenix 9 costs £859.99 in the 43mm size, £859.99 in the 47mm size and £949.99 in the 51mm size. Fitment changes with the watch size, so match the strap to the case rather than relying on the Fenix name alone: there are dedicated Garmin Fenix 9 - 43mm straps, Garmin Fenix 9 - 47mm straps and Garmin Fenix 9 - 51mm straps.

Silicone is the straightforward swimming partner. Nylon, leather, Milanese and metal are also available across those sizes, which gives you scope to change the feel of the watch once training is over.

Garmin wins this place on endurance emphasis, not on a published claim that it will never miss a pool length or draw a poor open-water corner. If Apple and Garmin are your final pair, our Apple Watch Ultra 4 vs Garmin Fenix 9 comparison looks at the broader serious-training decision.

Best for Android - Samsung Galaxy Watch Ultra 2

Samsung Galaxy Watch Ultra 2 is the natural all-round swimming and diving choice when you use an Android phone.

It has a 10 ATM water rating, a 40m dive rating and a dive computer, so it covers more than occasional pool logging. Its Super AMOLED display reaches 5000 nits; that high peak brightness helps with quick outdoor glances when reflections and direct sun make dimmer screens difficult to read.

• Water and dive rating: 10 ATM / 40m
• Dive computer: Yes
• Claimed everyday battery: Up to 60 hours
• Display: Super AMOLED, 5000 nits
• Case: Titanium

The watch is less endurance-led than the Garmin on its published everyday claim, but that is not the deciding factor for most Android swimmers. Phone fit comes first. A watch that integrates cleanly with the phone you already carry is more useful across training, commuting and recovery than a theoretically stronger option from the wrong ecosystem.

For regular swimming, start with silicone from the available Samsung Galaxy Watch Ultra 2 straps. Nylon, leather, Milanese and metal choices are also available for dry daily wear, so the dive-ready watch does not have to look permanently dressed for the pool.

Best for diving - Suunto Nautic S

Suunto Nautic S is the specialist choice when diving capability matters more than owning the most rounded everyday smartwatch.

Its 100 m water rating and 80m dive rating go beyond the other options here, and the watch includes a dive computer. Dual-band GPS using L1+L5 is valuable above the surface because it is designed to produce a more dependable track where satellite reception is difficult, while offline maps support wider outdoor use.

• Water and dive rating: 100 m / 80m
• Dive computer: Yes
• Claimed everyday battery: Up to 26 days
• GPS: Dual band (L1+L5)
• Maps: Offline maps
• Dimensions: 49.9 x 49.9 x 13.3 mm

This is a large watch, which is reassuring over a wetsuit but may feel excessive if your week mainly consists of short pool sessions and office wear. That is why it sits below Apple for the typical swimmer despite having the strongest dive rating in the shortlist.

The Suunto Nautic S costs £479 at the time of writing. Silicone is the obvious wet-use pairing, while the range of Suunto Nautic S straps also includes nylon, leather, Milanese and metal for changing how this specialist watch feels away from the water.

Best affordable option - Amazfit Active 3 Premium

Amazfit Active 3 Premium is the value-led choice for lighter swimming use when running, maps and everyday activity tracking matter just as much.

It has a 5 ATM rating, built-in GPS, offline maps and an AMOLED display. That is a useful everyday combination, but the lower water rating makes it a less convincing specialist pick than the other watches in this list if deep-water capability is central to your plans.

• Water rating: 5 ATM
• Claimed everyday battery: Up to 12 days
• GPS: Built in
• Maps: Offline maps
• Display: AMOLED
• Dimensions: 45 x 45 x 11mm

At £149.99 at the time of writing, it is comfortably the lowest-priced watch here. That makes sense if you are an entry-level runner who also swims, rather than an open-water endurance athlete or diver looking for a purpose-led tool.

Silicone remains the sensible water strap, but Amazfit Active 3 Premium straps also come in nylon, leather, Milanese and metal. That breadth is useful at this end of the market because an affordable watch can still be adapted for exercise and smarter daily wear.

Which swimming smartwatch should you choose?

Choose by your main swimming environment first, then consider phone compatibility, dive needs, case comfort and the strap you will actually wear between sessions.

• If you mostly complete structured pool sessions: Apple Watch Ultra 4 offers the strongest balance of swim use and ordinary smartwatch duties for an iPhone owner.
• If your sessions stretch into long open-water or multisport days: Garmin Fenix 9 is the endurance-first option, with several case sizes to help you balance readability against wrist comfort.
• If you use Android: Samsung Galaxy Watch Ultra 2 gives you the relevant phone fit without surrendering a serious water rating or dive computer.
• If scuba diving is the priority: Suunto Nautic S has the strongest dive rating here and is the more purpose-led choice.
• If price matters more than specialist swim capability: Amazfit Active 3 Premium is the accessible running-and-activity watch that can cover lighter water use.
• If you swim frequently: pair the watch with silicone so it does not hold pool water against your wrist, then keep leather, Milanese or metal for dry wear.

Open-water GPS endurance

None of the supplied manufacturer figures establishes how long these watches record an open-water swim with GPS continuously running. The table therefore shows claimed everyday battery only. Those claims are useful for understanding each watch’s general emphasis, but they are not interchangeable with GPS swim duration.

If your sessions are long enough that a failed recording would spoil the day, Garmin remains the sensible endurance-led pick. Charge before the swim rather than estimating GPS time from an everyday battery claim.

Length counting and route quality

There is no comparable head-to-head swim test here that proves one model will always count every length, handle every drill or draw the cleanest route. Water rating and feature fit are established; a guarantee of perfect logs is not.

That makes your training pattern the safer way to decide. Apple Watch Ultra 4 remains the best-balanced answer for most swimmers, while extended open-water training, Android ownership or genuine dive use gives Garmin, Samsung or Suunto a clearer reason to be on your wrist.

Frequently asked questions

These answers cover the care and underwater-use questions that matter once you have chosen your watch.

Will chlorine, salt water or hot tubs damage a smartwatch?

Chlorine and salt residue can cause cosmetic or operational problems if left on the watch, so rinse it promptly after swimming. Avoid hot tubs and saunas because heat and steam can affect water-resistant seals.

Do I need to enable Water Lock before I swim?

No, Water Lock prevents accidental screen input rather than increasing water protection. Starting a swim workout enables it automatically on Apple Watch Ultra 4 and Samsung Galaxy Watch Ultra 2.

Should I rinse the watch after a sea swim?

Yes. If you have swum in the sea, rinse the watch with fresh water and dry it thoroughly afterwards.

Can I listen to music through swimming headphones from the watch?

No, not while submerged, because Bluetooth audio does not work underwater. If you want music during a swim, use swimming headphones with onboard MP3 storage.