After doing awful things to my back, I've resumed lap swimming for the first time in two years. I used to swim a lot with my Ambit Peak3 (that incredible platform), and I've also swum laps with my Garmin Fēnix 5x when travelling. I'm currently enjoying swimming with my Suunto 9 (as wells as the WHRB before it), and find it to be an excellent swimming data logger.

My swimming needs

I need my watch to track three things:

  • HR
  • Distance covered, with alerts and clear display of data during the swim
  • Time taken for the swim


Anyone who has tried to capture their HR while swimming will have experienced problems caused by water: the force of the water pushes optical and chest-mounted HRMs, especially during the acceleration (push-off) phase of each stroke. The solutions as I've experienced them:

  1. Using a Mio optical HR, directly next to my Ambit, strapped tight. It can transmit through about 10cm of water, so the 2cm to the Ambit presents no issue. Comfortable, reliable, and I felt produced good data.
  2. Using Garmin's swimming-specific chest strap. The chest strap is made out of a static (ie non-stretch) material for the most part, and silicone-backed to keep it in place. The HRM has a memory, and the watch downloads data at the end of the swim.
  3. Using Suunto's HRM. Initially, this was a PITA, as the material they use for the strap stretches by about 30% when wet: it took me a minute to realise that I needed to wet the strap first, then put it on at a point that feels stupidly tight. Once on, and swimming, it feels about the same as when I'm wearing it dry, and most importantly stays in place. These extra steps - undocumented by Suunto - put me off their solution for a long time, but now I have a better understanding I really enjoy their monitor, as it's smaller than the Garmin, and most importnatly, means I don't need to buy an extra piece of matérial.

I know the Spartan series can use their optical HRM during swimmnig, but I don't imagine it being anywhere near as accurate as the chest strap.

Distance covered

I find swimming relaxing, and when I swim, I lose track of which length I'm on, and by extension, how far I've swum. I know 22 minutes is about 1km, but there's no fun in that. To the best of my knowledge, all watches work the same way: configure the size of the pool, and then each time the accelerometer indicates a 'spike', distanceSwum = (distanceSwum+$poolSize). As long as I execute a good push-off, I notice all watches are about equal in their accuracy of length recording.

Garmin - being Garmin - have a lot of options for notifications during siwmming, which I like: buzz + beep after interval x, reminds me it's time to do another length of crawl (I do one crawl, three breast).

Suunto - being Suunto - have slightly fewer options, but they work for me. It vibrates at 50% of the distance specified at the start of the swim (a 'target') and again at 100%.

Suunto UI Sans

Where the Spartan series really excels in swimming is the bigger screen: at 320x300 pixels, it is a lot larger than the 240x240 pixels on current Garmin units. This screen size, coupled with their font, Suunto UI Sans, developed by the Typolar Type Foundry, makes reading the distance I've swum easy, while still looking elegant. I've long been a fan of Suunto's fonts, and appreciate the evolution of Underware's earlier Suunto font that we have today:

Starting from 2012 Typolar has worked with SUUNTO to create readable and clear product UIs for extreme conditions. We have designed a set of fonts for these very specific products and their varying technical constrains. Suunto UI Sans font family works seamlessly on both low and high resolution displays due to its inventive visual concept. Its recognizable character has a significant role in the branding of product websites and apps. Suunto UI Sans was awarded with iF Design Award as a part of SUUNTO Movescount service in Munich in 2014.

As an aside, if one explores the file on a Mac, one can find the Suunto font (SuuntoSemiCondensed.woff, amongst others).

Time taken

It start, it stops, it applies time to lengths. lovely.

Other swimming metrics

My watch tells my my SWOLF (this does not mean 'swimming wolves', and is not a nautical equivalent to hoursepower), cadence ('stroke rate'), and tries to identify which stroke I'm swimming. None of these are of particular interest to me, although I do like to see an estimation of VO2max (it makes me feel better to see my swimming VO2max as lower than my running or my cycling VO2max, as it explains the modicum of breath play I experience after extended sessions of front crawl).