Big test: Four smartwatches compete on swim tracking

We put the Apple Watch, Gear Sport, Vivoactive 3 and Fitbit Ionic to the pool test

This year we've seen fitness trackers and smartwatches broaden in scope to cover more types of sport and exercise, of which swimming has been a major one.

A handful of smartwatches have promised to go the depth when it's time to hit the pool, tracking everything from stroke type to SWOLF (which is essentially a measurement of your swimming efficiency). Question is, who does it best?

Read this: The best waterproof fitness trackers

So with that question in mind, we took four of the biggest sports-focused smartwatches of the year into the pool to see how they compare on accuracy, data captured and general usefulness for swimming. Here are the results of our swimming smartwatch big test.

Samsung Gear Sport – 4th place

Big test: Four smartwatches compete on swim tracking

When I first tested the Samsung Gear Sport in the pool, it was a sinker. The lap tracking was way off, to the point I thought I might have a faulty watch. A subsequent update has somewhat solved the problem, but it's still not perfect. Initially the Gear Sport was significantly overcompensating distance, which seems to be a bit less dramatic post-update, though during one 550 yard swim it registered 649 yards, counting 26 lengths instead of the 22 I actually did. Not great.

One of the big promises of the Gear Sport was a partnership with Speedo On, an integration that Gear Fit 2 Pro users are already enjoying, but sadly it's still not available for the smartwatch. Samsung couldn't tell me exactly when it's coming but said it should be by the end of the year.

Wareable verdict: Samsung Gear Sport review

Onto the good points of swimming with the Gear Sport. I like how you can see a lot of information on the screen at once, and that all of this can be customised. You can set lap cues right from the watch too. At 67g and 43mm wide the Gear Sport is also very comfortable to wear in the pool. Like the Apple Watch, the Gear Sport will "lock" the screen when you begin a swimming workout. This minimises the risk of the display mistaking the water for finger prods.

One big drawback of the Gear Sport is that you can only set the pool length to one of the three pre-set options Samsung offers, and that won't change until Speedo On is up and running with the watch.. This was a problem on one occasion where I had to use a different pool to my regular one, which was slightly larger, but I couldn't tell the watch.

The post-workout data is probably what Samsung does best right now, as Samsung Health gives you a nice dollop of data to look over in an easy-to-read fashion. Garmin and Apple go deeper, but you can see distance, stroke total, average pace, max pace and length total, all set in a very clean, glanceable layout.

Big test: Four smartwatches compete on swim tracking

You can also see your average and best SWOLF recordings, along with stroke types, though that last one is pretty poor. On one swim it told me all of my strokes were butterfly when in fact I was doing a mixture of everything but.

Essential reading: Swimming with heart rate monitoring wearables

Interestingly Samsung does track heart rate, and the graphs have looked convincing enough, but given that optical sensors usually struggle with water it's unlikely to be very reliable.

Even so, if you're really into the granular nitty gritty, a lot of this will be useless to you without better accuracy. Hopefully when Speedo On is available, things will get better.

Features: 3/5

Accuracy: 2/5

Post-swim analysis: 4/5

$299,, Amazon

Fitbit Ionic – Bronze medal

Big test: Four smartwatches compete on swim tracking

While the Flex 2 offered some limited swim tracking, things have got more serious with the Ionic smartwatch. One of the benefits of a display is that you can start and customise pool sessions from the wrist, and it also means you've got a live readout too.

Starting a session is easy: You can tap the top right button and then just scroll along to 'Swim'. In the top left hand corner is the settings cog that will let you customise the data screens, pool size and lap cues.

Wareable verdict: Fitbit Ionic review

Unlike the Gear Sport, the Ionic lets you set the exact pool length, in both metres and yards, right from the watch. You can choose which stats are displayed too, but where Samsung has two alternating screens of data, the Ionic gives you one with two fixed stats, and one in the middle that scrolls through other metrics that can be selected in the settings. The Gear Sport fits more on, but the Ionic has nice big numbers that are easier to read when the goggles are starting to fog up.

Big test: Four smartwatches compete on swim tracking

As for accuracy, I found it to be better than Samsung but not as good as the other two in this test. Again it was a case of over-counting, though not as dramatically as the Gear Sport. On the same swim that the Gear Sport read four extra lengths, the Ionic went over by two, adding 50 yards that I didn't actually swim. None of these are perfect on accuracy, and 50 yards was the biggest disparity I've had with the Ionic in a handful of pool sessions.

Post-swim data is pretty basic; you'll see your distance, pace, lengths, calories burned and lap breakdown, but right now there's no SWOLF score. That may be enough for many people, but I do think some users will be left wanting more analysis, particularly in the set breakdowns.

Features: 4/5

Accuracy: 3/5

Post-swim analysis: 2/5

$299,, Amazon

Garmin Vivoactive 3 – Silver medal

Big test: Four smartwatches compete on swim tracking

Okay, I cheated a bit on this one and actually tried both the Vivoactive 3 and the Fenix 5S in the pool. The purpose of this piece is to focus on smartwatches, and though I think you can make that case for both, the Vivoactive 3 is closer to fitting that profile.

Either way, the swim tracking is the same on both. The only drawback of the Vivoactive 3, and the reason I tested the Fenix 5S as well, is its lack of buttons. You have just one, which means you can't do quite as much during the workout, and it means you really need to get everything set up before heading into the pool as that screen can be a nuisance to use when wet.

Even with one button you can still tap when you finish a set or pause your workout. The Fenix 5S's other advantage is that it supports open water swimming, while the Vivoactive 3 does not.

Wareable verdict: Garmin Vivoactive 3 review

With fewer buttons you can only have two metrics on the display at once, and again, I'd advise setting those up before dunking yourself. As soon as you start a pool swim it disables the heart rate sensor, so you'll get no data like you do on the Gear Sport and Apple Watch.

Big test: Four smartwatches compete on swim tracking

I've found Garmin's accuracy to be very good. On one swim against the Apple Watch the Vivoactive 3 came in just one lap extra; on another against the Gear Sport the Fenix 5S embarrassed its rival by getting 26 laps bang-on. There's sometimes the odd discrepancy, but Garmin's pool tracking is very good, which is all the more impressive when it's relying on accelerometer data and not GPS (which you can't do inside and underwater, obviously).

After your swim there's a lot to look at. The Garmin Connect app breaks down the workout into different sections: pace, timing, dynamics and calories. In these you can view everything from your average stroke rate to your pace to your SWOLF. It labels your intervals with the predominant stroke, but doesn't break it down length by length like the Apple Watch does.

Features: 3/5

Accuracy: 4/5

Post-swim analysis: 4/5

$299,, Amazon

Apple Watch Series 3 – Gold medal

Big test: Four smartwatches compete on swim tracking

This was a tough one, and honestly Garmin and Apple were almost on an even keel. When I started out this test I thought Garmin would have it, but I was then reminded how far the Apple Watch has come with activity tracking, and as a swim tracker it really is excellent.

First of all, accuracy has been only just short of perfect. Aside from one session where it was a little off, the Series 3 has had distance and lengths spot-on, both in the live screen and post-swim analysis.

Wareable verdict: Apple Watch Series 3 review

Tracking is very easy from the watch too, however you can only set the metrics you want displayed from the iPhone app, not on the watch itself, which isn't great when you've left your phone in your locker and are already waist deep in water. You can set the pool length though, which is more of a biggy. Worth mentioning the Apple Watch supports open water swims too, which the Vivoactive 3 doesn't.

Once you start a workout, the screen will lock and you'll just be able to see a single screen showing the four metrics you set in the iPhone app. To unlock it you need to roll the digital crown, which will let you swipe left to end/pause the workout or right to the music player.

Big test: Four smartwatches compete on swim tracking

Once done, your workout will be automatically synced to the iPhone's Workout app. I really love the layout of this, and not just because I'm a sucker for lots of vibrant colours. Like Samsung, Apple makes this information really easy to digest. One thing it's lacking is Swolf, which Garmin does offer, but on the plus side I've been super impressed with how accurately it's managed to detect each different stroke.

The Apple Watch also tries to detect heart rate, but it's patchy, and in one case it told me at the end of the workout that "there were not enough heart rate measurements to create a chart". Again, optical sensors and water don't get along brilliantly, so I'd pretty much discard this for now.

Also worth mentioning that while I tested this with the Series 3, the Series 2 has performed just as impressively. The one advantage of the Series 3 is that you can have LTE, so you don't need to be away from messages and calls while in the pool.

Features: 4/5

Accuracy: 5/5

Post-swim analysis: 4/5

$399,, Amazon

Wareable verdict

While the Apple Watch comes out top, it was a very close call against Garmin, which does have a couple of its own advantages, Swolf tracking being a big one. My biggest disappointment was Samsung, but once the Speedo On integration is working with the Gear Sport I'll be sure to take it back in the pool to see if there's any marked improvement. As for the Ionic, it's not terrible by any stretch, but serious swimmers will be left wanting.

Right now, Garmin and Apple deliver best on accuracy and data, so if you're looking for a new pool buddy I'd be happy to recommend either. For me though, the Apple Watch just slips into first place.


  • ChristianP says:

    "The purpose of this piece is to focus on smartwatches, and though I think you can make that case for both, the Vivoactive 3 is closer [than the Fenix 5S] to fitting that profile."

    What smartwatch features does the Vivoactive 3 have that the Fenix 5S doesn't?

    • adammiarka says:

      Garmin Pay

  • yogibimbi says:

    Curious the omission of any Android Wear watch. My Mission is at least perfectly capable of surviving the water, I would like to see what software you guys think is the best that should run on it.
    Also, bummer that the Apple watch requires an iDevice somewhere in the mix, I would like to buy one, because it's the best all around watch feature wise, what with LTE on board, Apple Pay and waterproofness, but I won't ditch my Xperia Z5 compact, and plans to get a Galaxy Note S8 once it is reaching a reasonable price level, just now. No SD card storage on any iDevice is still holding me back.

  • pekz says:

    I have the Polar M600, which is an amazing android smartwatch that has been spot on with my 50 pool swims, except once. (I typically swim 1 mile freestyle in a 25 yrd pool, but I mix up speed and sets.) The optical heart rate remains on during the swim session and is reasonably accurate for underwater swimming (proper placement on your wrist is important). I have found the Polar M600 to be a great smartwatch and and great sports watch. No watch is perfect, but this watch perfectly suits all my needs.

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