Waterproof fitness trackers are rated using the ATM measurement which stands for the atmospheric pressure unit the device can withstand under water. Though the depth is only estimated, a waterproof fitness tracker with 1ATM rating means the device can withstand up to 10 meters (33 feet) water depth, while 4ATM means up to 40 meters (132 feet), and so on.

Most water-resistant fitness trackers (not waterproof) are rated up to 1ATM because they can withstand water splash, rain and human sweat, definitely not a dive into the water. This means they can withstand up to 10 meters under the water ‘theoretically.’ That withstanding, a waterproof fitness tracker for swimming is required to have as much ATM as possible to avert strong pressures even at low depth swimming while securing the device. Yes, the ATM rating is also deceptive; some activities may subject a fitness tracker to more atmospheric pressure even at low water depth to break its resistance level.

Many manufacturers of fitness devices have only produced a few devices with more than 1ATM. Fitbit, one of the most popular fitness tracker makers has only two devices with waterproof; Flex 2 (wristband) and Ionic (smartwatch), though Fitbit will always make any top list of fitness trackers of 2018 sequel to product battery life and accuracy. Garmin, Apple and TomTom are also among our top waterproof fitness trackers of 2018.

Apple Watch Series 3

Water rating: 5 ATM

Battery life: 1 day

GPS: Yes

Price: $399

The Apple Watch Series 3 is one of the top fitness trackers available now. It’s a strong demonstration of Apple’s latest smartwatch technology. Though it operates only in the iOS ecosystem, Series 3 is a top class waterproof device and the first standalone wearable gadget from Apple; it can receive calls, text messages and other smartphone features independently with its mobile and 4G signal. The fitness tracker can monitor heart rate and it’s fully equipped with multiple sports sensors and applications embedded to function with its GPS. With its 5ATM water rating, the device can be submerged up to 50 meters. The only flaws with this waterproof fitness tracker is the battery life which can only last for a day.

Apple Watch

Apple Watch has collaborated with a medical company to develop an EKG sensor.

Garmin Vivoactive HR

Water rating: 5 ATM

Battery life: 3 days

GPS: Yes

Price: $249.99

The Garmin Vivoactive HR is a GPS-enabled fitness tracking device for multiple sports. It's amazing with its colour touchscreen and offers on-device sports apps for hiking, swimming, rowing, biking, golfing, running and others. Vivoactive HR measures heart rate; offering multiple vibration alerts, calories burned, pace, mileage, run/walk intervals, and has well-advanced fitness tracking features such as auto lap, auto stop and activity stats. Vivoactive HR uses speed and distance on coordinate against inclination to measure 3D speed.

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Garmin Forerunner 735XT

Water rating: 5 ATM

Battery life: 5 days

GPS: Yes

Price: $499.99

The Garmin Forerunner 735XT remains one of the top waterproof fitness trackers regardless of its release date, May 2016. It's a triathlon watch, slim design, lightweight and also one of the best products from Garmin packed with multiple features and strong fitness tracking accuracy. Most professional athletes use 735XT for running, swimming, and cycling, though it supports other sports. The water rating is up to 50 meters, that's 5ATM. Garmin Forerunner 735XT offers premium swim tracking details with various modes. It has good battery life; can serve up to five days, clear screen, and well-advanced fitness tracking features.

Garmin best fitness trackers

Fitbit Ionic

Water rating: 5 ATM

Battery life: 5 days

GPS: Yes

Price: $299.95

The Ionic from Fitbit is a top class fitness tracker with all the latest technology from the makers. As a smartwatch, Ionic can be used for calls, text messaging, emails, WhatsApp and more. The waterproof fitness tracker delivers stunning 5 days battery life at maximum use. Considering the embedded features, accuracy and the days it can go without a charge, Ionic would take a while to leave the list of top waterproof fitness trackers. The water rating is 5ATM. Other features available in Fitbit Ionic include built-in music storage, Fit it Flyer headphones, and advanced apps for exercising. 

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Fitbit Flex 2

Water rating: 5 ATM

Battery life: 5 days

GPS: No

Price: $99.95

Individuals not ready to deal with complex functionalities such as GPS, NFC, multiple apps, and others alike go for Fitbit Flex 2. It's a very durable wristband with no screen but a series of LEDs for calls notifications, text messages, alarm, reminder, and your fitness activity. The device has provision to interchange accessories based on your events. It can measure sleep quality, stationary times, steps, swim duration, and calories burned accurately.

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TomTom Spark 3

Water rating: 4 ATM

Battery life: 2 days

GPS: Yes

Price: $169.99

The Spark from TomTom is a well-respected fitness tracker with multiple functions. Spark has up to four models but each represents a good water rating while also sharing almost the same feature. It’s an excellent option for swimming, running, running, cycling and treadmill with its various modes. The pace measurement is very accurate running one of the best GPS systems. It can measure swim distance, stroke rate, speed, calories burned, and the number of laps. With Spark, you can slit your swim into different sessions and the device will notify you when you need to change power or switch stroke. TomTom Spark is the only device on our top waterproof fitness trackers of 2018 with 4ATM water rating.