Keen swimmer? Fitness junkie, or just want to get healthier with regular visits to your local pool? Then you need an activity tracker that is both waterproof and tracks your swimming strokes and distances. See all activity tracker reviews.

Also see: Best Fitness Tracker Deals

Here we gather the best swimming trackers to see what each boasts in terms of functions, with a particular interest in swimming modes. For regular activity trackers read our Best Fitness Activity Tracker round up.

Best swimming trackers: get in the water

Activity trackers tend to stick to dry land for most of their functions: step counts, floors climbed, GPS-based runs, and so on. Some, like the Fitbit Blaze, have worked in multi-sports functions to track workouts that bring in fitness activities such as cycling, circuit training, yoga, martial arts, golf, tennis and weights for example. See Which Fitbit is Best?

But few allow for swimming activity, which is a shame as it’s one of the most popular and effective fitness exercises. The simple reason for this exclusion is that most activity trackers are not waterproof.

Waterproof rating: Most devices are rated to ATM, or one Atmosphere. ATM is the atmosphere pressure unit that tells you how effective a device is in withstanding the pressure until a specific depth. 1 ATM is waterproof for ten metres of water pressure. 3 ATM would be waterproof up to 30 metres.

With the exception of the new Fitbit Flex 2, the Fitbit range, for instance, is water resistant but not waterproof. They can take a burst of rain or the sweat you’ve produced on a run, but not a dive into deep water. Most are rated up to 1 ATM, meaning theoretically they should be able to be submerged in water up to 10 metres in depth – way deeper than most of us swim! The Fitbit Surge is even rated at 5 ATM, so it theoretically can be submerged to 50m depths, but again Fitbit says you shouldn't swim or even shower in it. See: Are Fitbits waterproof?

ATM ratings are somewhat illusory. Even if a device is above the depth it's rated for, it could still suffer water ingression if it is subjected to an activity (asuch as swimming) that creates pressure on it that then exceeds that depth rating. The ATM depth is measured in static pressure. Water pressure can change quickly, such as when you move your arm when swimming. This means that you can surpass those theoretical depths in reasonably shallow water.

According to our own tests swimming with a Fitbit didn’t wreck the tracker, but we can’t guarantee yours won’t stop working. And anyway there’s no benefit to swimming with most trackers as they don’t register what you’re doing in the pool. You might as well just remove your tracker, and get on with your swim.

Other elements of the modern tracker also preclude swimming: the optical heart-rate function is inaccurate in water; and the GPS is useless in indoor pools.

What you need is not just a waterproof tracker, but one that monitors, measures and records your swimming strokes, distance, length times, and other swimming metrics. ATM ratings are an important indicator, but you need to check the manufacturer has specified that the device is properly waterproof. All the trackers tested here are waterproof enough for swimming, although maybe not deep-sea diving!

Swimming trackers: why swimming is good for you

Swimming burns calories, so helps you lose weight, and it’s praised for its cardiovascular health benefits. Swimming uses many muscles in your body, and makes your heart and lungs work hard to supply them all with oxygen.

Because water is about 800 times denser than air, you can work harder and burn more calories in a pool than out of it. Even a gentle swim can burn over 200 Kcal in half an hour and a fast front crawl can burn as many calories as an 8mph run.

Best swimming trackers: swimming metrics

Lengths swum: Unless you stick to swimming widths of the pool, measuring the number of lengths swum is a basic swimming metric. Yes, you can count them yourself in your head, but you could say the same for the number of steps you walk – and that’s ridiculous.

Pace: You want to increase your swimming pace, and swim trackers should recognize when you turn so remember to set the pool length before diving in.

Stroke rate: used to find out more about your swimming technique, rhythm and timing. This can be the strokes you take per minute, and also how many strokes you take per pool length. If your stroke rate is too low, you might be moving your arms too slowly. If your stoke rate is too high, your stroke might be too short for optimal performance.

SWOLF: SWOLF stands for “Swim Golf”. Golf? Yes, don’t worry about that. It’s a combined metric of speed and effort – a measurement that adds the number of strokes you take with the amount of time it takes to swim the length of a pool. If you swim a 25m pool in 24 seconds using 18 strokes that’s a SWOLF score of 42. Get below 40 for great SWOLF scores. Like in golf, the aim is to get your score as low as you can.

Obviously SWOLF scores vary on the length of the pool, so try to keep to one length of pool. SWOLF-measuring trackers will have settings for different-length pools.

Fitbit Flex 2

Fitbit Flex 2
  • RRP: £79.99, US$79.95

Waterproof: Yes, to 50 metres (5 ATM)

GPS: No

Measures: Steps, distance, calories burned, daily and hourly activity, sleep quality, swim duration.

Alerts: smartphone call and text notifications, but not Caller ID

The Fitbit Flex 2 is Fitbit's first fully waterproof activity tracker, and one that's ready to measure swimming as one of your fitness regimes.

Much like the original Flex that it replaces the Flex 2 is minimalist in looks (Fitbit's slimmest tracker yet) and display. You see how far you are with hitting your daily targets by a series of five discreet lights that each represent 20 percent of your total reached so far. If you want to tell the time on your tracker or see all the stats right there on your wrist you should consider another tracker.

Fitbit is clearly aiming the Flex 2 at women, but it's a perfectly acceptable tracker for men, although maybe less so for the interesting bangle and Pendant tracker holder accessories that Fitbit offers for the Flex 2.

The swimming stats are quite basic: the Flex 2 measures your swim duration and calculates the calories burned dueing that splashy session. The Flex 2 is a perfectly good tracker for the casual exerciser and swimmer, but those wishing for detailed swimming metrics (including strokes, pace and SWOLF) should consider the other swim trackers featured here.

See Fitbit Flex 2 review.

Fitbit Flex 2: £79.95 (US$99.95; €99.95)

Polar Loop

Polar Loop
  • RRP: £79, US$99.95

Waterproof: Yes, to 30 metres (3 ATM)

GPS: No

Measures: Steps, distance, speed (A360/M400), heart rate (A360; M400 requires chest strap), calories burned, sleep quality.

Alerts: smartphone notifications (A360/M400/Loop 2); inactivity alerts (Loop 2)

While these Polar wristbands are decent activity trackers with all the basics and more the fact that they are waterproof does not make them a proper swimming tracker.

They don’t measure any swimming metrics (except how long you were in the pool), so really just allow you to swim and bathe without removing the wristband. This should still count your swimming as exercise but as the heart-rate function is impaired in water any idea of calorie burn is similarly untrustworthy.

The A360 boasts wrist-based heart-rate monitoring; the others require a chest strap. Polar does recommend even A360 owners use the chest strap for the most-accurate heart-rate readings. Runners will appreciate the training features of the A360 and M400, but that doesn’t make them any better for swimmers.

By all means get one of these Polar trackers if all you want is a waterproof activity tracker but look elsewhere (see trackers below, including Polar's own A800) if you want to measure and monitor your swimming in any detail. See Polar Loop review.

Polar Loop 2: £89.50 (US$119.95; €119.90), available at Amazon.

Polar M400: £119.50 (US$179.95; €159.95), available at Amazon.

Polar A360: £149.50 (US$199.95; €199.90), available at Amazon.

Polar V800

Polar V800
  • RRP: £339, US$499.95

Waterproof: Yes, to 30 metres (3 ATM)

GPS: Yes

Measures: Steps, distance, speed, heart rate (requires chest strap), active time, intensity levels, calories burned, temperature, sleep quality, stroke style, swim stroke rate, SWOLF.

Alerts: smartphone notifications (A360/Loop 2); inactivity alerts

Unlike the cheaper Polar trackers the V800 is a serious swimmer's The Polar V800 is a multi-sports watch, specializing in running, cycling and swimming, and so is aimed at triathletes. It supports both pool and open-water swimming. An open-water setting will clock your progress via GPS.

It’s waterproof up to 30 meters and can measure your heart rate even in water but this requires an additional sensor that can track your pulse underwater. You have to strap the Polar H7 belt to your chest to check your heart rate, which makes it unsuitable for more casual users who prefer a unified tracker with wrist-based heart-rate monitor.

In the pool the V800 analyses your swimming technique using stroke rate per minute or pool length. It also uses SWOLF scoring (sum of time and strokes per pool length) to get a more accurate picture of your style and strength.

The V800 recognizes four types of swimming stroke: Freestyle/crawl; Backstroke; Breaststroke; and Butterfly.

The V800 lets you create and customise profiles for different sports. Back on dry land Running Index analysis predicts your event finish times for 5K, 10K, half marathon and marathon runs.

At well over £300 (US$499.95) the Polar V800 is a serious piece of kit and probably not for the casual keep fitter or pool goer. There are less expensive swimming trackers you can consider, so read on.

Misfit Speedo Shine

Misfit Speedo Shine
  • RRP: £69.99, From US$79.99

Waterproof: Yes, to 50 metres (5 ATM)

GPS: No

Measures: Steps, distance, calories burned, sleep quality and duration, swim laps and swim distance.

Alerts: smartphone notifications; inactivity alerts; alarms

Neither the Misfit Speedo Shine or Shine 2 has to be worn on the wrist. You could instead attach it your swimming costume. It can’t, however, measure your heart rate – especially not on your trunks! Back on dry land you can clip it onto your shirt or belt.

Both of these waterproof Shines track your swimming laps and distance, but not the style of your strokes. They count swim laps for 25- and 50-metre pools (you pre-set the length), and count down a set swim time. That means it’s not much use in open water, so triathletes should look elsewhere (see the Polar A800 above).

You triple tap to tell the Shine that you’re about to start swimming. Misfit says that the number of laps swam and distance is validated by Speedo’s Aqualab tests.

Once you’ve finished your exercise you tag it, and choose from a range of sports including swimming, cycling, basketball, football, tennis and running.

The Shine 2 is more sophisticated with vibration alerts for call and text notifications, movement reminders, and alarms

Unlike most trackers the Shines don’t feature a rechargeable battery. Instead they have a replaceable six-month battery, which means you don’t have to worry so much about it running out after a few days. The silver disc comes with both a White and Black sport band, and action clip and a clasp.

Read our Misfit Shine 2 review.

Shine 2 Swimmer: £96.88 (US$119.99; €115), available from Amazon.

Withings Activité Pop

Withings Activité Pop
  • RRP: £119, US$119.99

Waterproof: Yes, to 50 metres (5 ATM)

GPS: No

Measures: Steps, distance, calories burned, sleep duration, sleep quality, swim duration

Alerts: alarms

The Withings Activité looks more like a watch than any other activity tracker. It has an analogue display, and even analogue activity feedback. Don’t worry, the mobile app is fully digital, featuring activity badges, leaderboard, healthy reminders and activity insights.

Activité doesn’t offer a wealth of swimming stats, but enough for the casual get/keep-fit swimmer. It recognizes your swim session, and logs the duration and calories burned. It’s a good choice if you want the looks of a classic watch, the basic step/distance counts, sleep monitoring, and core swimming stats.

It works on a button cell providing a battery life up to eight months, so there’s no need to charge it every few days. To recharge the battery, simply change the button cell.

There are three versions of this watch that is smart in more than just functionality. The Pop is made of stainless steel with PVD coating; the Steel just stainless steel; and the Sapphire from Swiss-made stainless steel. The Sapphire also boasts Sapphire Glass (compared to the others’ Mineral Glass) and a French calf-leather strap.

The Pop is available in Blue Azure, Wild Sand, Shark Grey and Coral Pink. Steel is black only, and Sapphire is in either Black or Silver.

Activité Steel: £139.95 (US$149.95; €169.95). Available from Amazon.

Activité Sapphire: £320 (US$450; €390). Available from Amazon.

iHealth Wave (AM4) activity tracker

iHealth Wave (AM4) activity tracker
  • RRP: £59.99, US$79.99

Waterproof: Yes, to 30 metres (3 ATM)

GPS: No

Measures: Steps, distance, calories burned, sleep duration, automatic workout mode, swim duration, recognition of swim stroke, number of movements, and movements per minute distance.

Alerts: inactivity alerts; alarms

The iHealth Wave (AM4) is a waterproof activity tracker that looks like a regular watch but measures your swimming strokes as well as the number of steps you walk or run each day, distance travelled and calories burned. And at night it analyses the quality of your sleep, so it offers 24-hour personal monitoring. Read our full iHealth Wave Review.

The swimming stats breakdown your swimming session by stroke: breaststroke, crawl and backstroke. If the Wave doesn’t recognize what you’re doing it records the stroke as “Other”.

It measures the length of time you swim with each stroke, number of strokes, strokes per minute, and calories burned while swimming.

The iHealth Wave is actually just one part of a large family of health-monitoring devices, including wireless scales to measure your weight (see Best smart digital scales), a pulse oximeter to check the oxygen levels in your blood, and blood-pressure monitors, as well as glucometers to measure your glucose levels.

It’s not as good looking as the similar Withings Activité watch but it’s sporty enough in design for most people who want their tracker to look more like a watch than a wristband.

Moov Now

Moov Now
  • RRP: £59.99, US$59.99

Waterproof: Yes, to 3 metres (0.3 ATM)

GPS: No

Measures: Active minutes, calories burned, sleep duration, sleep quality, swim lap time, turn time, resting time, and swimming pace.

Alerts: inactivity alerts; alarms

Moov Now is an affordable tracker that’s a bit different. It essentially acts as a coach to assist you during workouts, but it can also track your daily activity and sleep. Unlike other trackers the Moov Now doesn't track steps – instead you see a breakdown of your most active minutes in a scrollable timeline.

Moov chose to encourage an active lifestyle through a focus on active minutes rather than steps, etc. Active minutes take into account intensity and other activities such as swimming and cycling that can’t be represented as steps. Achieving active minutes requires a higher expenditure of energy that will be more effective towards living a healthy lifestyle.

Where the Moov Now really excels though is in its coaching. The app offers a 'get toned in under 10 minutes' workout that has different move sets to help change things up from day to day. It actually talks you through your workout with real-time audio coaching for running, cycling, cardio boxing, and body weight.

When swimming you'll be able to monitor swim lap time, turn time, resting time, and swimming pace. Moov analyzes each stroke to detect whether you swam freestyle, breaststroke, butterfly, or backstroke. Your swimming will improve by seeing your detailed lap breakdown and highlights like stroke rate, distance per stroke and more.

You can see when you swam your fastest 100 metres and how long it took, or know your longest continuous swim and try beat it each time. Read our full Moov Now review.

Garmin Vivoactive HR

Garmin Vivoactive HR
  • RRP: £209.99, US$249.99

Waterproof: Yes, to 50 metres (5 ATM)

GPS: Yes

Measures: Steps, distance, floors climbed, calories burned, sleep duration and quality, swim lengths, distance, pace, swim stroke count/rate, SWOLF, golf shot distance

Alerts: smartphone alerts; inactivity; alarms

The Garmin Vivoactive HR is a multi-sport GPS smartwatch with colour (although low 205-x-148 pixel resolution) touchscreen and an amazing range of on-device sports apps including: running, biking, walking, rowing, pool swimming, golfing, ski/boarding, and even stand-up paddle boarding.

The Garmin Connect app gets to know you and delivers the insights to help your fitness programme progress. It will deliver cues for you to move if you’re not on track to meet your step goal, and celebrate when you do. It also offers healthy tips from experts that become like virtual coaches.

It has a full set of swimming features (although triathletes should note that it’s pool only not open water), with stats such as total and interval distance, pace, stroke count, and stroke type. The swimming app calculates your efficiency with SWOLF. Interval Count lets you seamlessly pause and then resume your workout. At the end of a workout, view your summary data, which includes interval and session averages, overall time and personal records.

Like most, the heart-rate monitor won’t work in water.

We like the fact you can set up multiple vibration alerts for heart rate, pace, run/walk intervals and more. Training features include Auto Lap and Auto Pause. You can get post-run summary with stats such as total mileage, calories, average pace and overall time.

The GPS-enabled cycling app measures time, distance, speed and calories, with a bike speed/cadence sensor.

Golfers will appreciate the Vivoactive HR measuring shot distance – it calculates exact yardage for shots from anywhere on course, says Garmin, which has a downloadable database of over 40,000 course maps worldwide.

For skiers Vívoactive HR measures 3D speed by calculating the speed and distance on an incline versus latitude and longitude.

If you’re a skier, golfer, runner and rower we salute you (and your free time), and think the Garmin Vivoactive HR should be on your shopping list. Its swimming features are impressive too.

TomTom Spark

TomTom Spark
  • RRP: £109.99, US$149.99

Waterproof: Yes, to 40 metres (4 ATM)

GPS: Yes

Measures: Steps, calories, distance, active time, heart rate (Cardio, Cardo + Music), location, sleep, multi-sports, swimming speed, pace, stroke rate and number of laps, calories burnt and swim distance.

Alerts:

The TomTom Spark is a well-respected activity tracker for swimmers and other sporty types. It has multi-sports modes for running, treadmill, cycling, gym and swimming.

As you’d expect from TomTom, the Spark range features GPS for location tracking and accurate pace measurement. The GPS won't operate in indoors swimming pools.

The Swimming mode is excellent, measuring speed, pace, stroke rate and number of laps, calories burnt and swim distance.

You can break down your swim into sets and sessions of differing effort levels. The Spark can buzz each time you need to switch stroke or power effort. The Goal mode offers an in-pool view of how your swimming session is going, and will buzz you to celebrate over achievement.

Running measures duration, speed and pace for the entire run and km by km, calories burnt, number of steps and heart rate and heart rate zone minute by minute. Cycling: Duration, speed and pace for the entire ride and km by km, calories burnt, location and heart rate and heart rate zone.

TomTom claims battery life is up to three weeks; 11 hours for GPS use; and 5 with GPS, heart rate and music added in.

While the user interface is excellent the display isn’t touchscreen. You need to navigate via the four rather clunky physical buttons.

There are four models of TomTom Spark. The entry-level Spark lacks the built-in heart-rate monitor found in the Spark Cardio, Spark Music and Spark Cardio + Music. The Spark Music can carry 500 songs to train to, and the Spark Cardio + Music boasts both the heart-rate monitor and the song storage.

Compatible with bluetooth headphones, the Music versions mean you can leave your smartphone at home when exercising. There’s also audio feedback on your performance.

You can customize the watch with different rubber straps, and there’s a Premium edition (£219.99), which includes a strap with metallic clasp as well as the fitness strap.

TomTom Spark Cardio: £149.99 (€199). Available from Amazon.

TomTom Spark Music: £149.99 (€199). Available from Amazon.

TomTom Spark Music + Cardio: £189.99 (€249). Available from Amazon.

XMetrics FIT

XMetrics FIT
  • RRP: £155

Waterproof: Yes, to 3 metres

GPS: No

Measures: swim duration, total distance, length count, pace, distance per stroke (PRO only), strokes per length, SWOLF, calories burned.

Alerts: None

XMetrics FIT is unique as it’s not a wristband but actually attaches to the back of your goggle straps on your head. The company believes that the back of the head is the most solidal part with every body’s movement and is therefore the best position to detect biomechanical data.

It can sense the style of stroke too: measuring Freestyle/crawl; Backstroke; Breaststroke; and Butterfly.

It comes with a set of waterproof headphones, so you can receive personalized audio feedback about your performance while swimming. This means you don’t need to wait until the end of your training session for your stats.

There are two models: the FIT and the PRO. While the FIT is enough for the casual keep-fit swimmer, the PRO can help you create more detailed training programmes. The Pro links with a mobile app via Bluetooth, and goes further than the Fit with cycle rate, Stroke Index Efficiency, split laps, and interval detection.

XMetrics Pro: £225. Available from Amazon.