Fenix 5 Plus open water inaccuracy

My new Fenix 5 Plus is very in accurate in open water. First time I did around 1,500 meters but it just showed 250. Second time I did around 2,500-3,000 but it just showed 1,500. However the map seemed to track what I did correctly. Also, I had 1,000 meters alerts on but instead it gave me 500 meters alerts. Data recording was set at "every second" mode and I tried all three GPS modes. I also have version 4.20. First reply from Garmin Spain was: "GPS measurement in open water will never be as accurate as when running or cycling because GPS looses connexion when paddling, so we don't think your watch has any problem". Anyone else?. Not surprisingly, the Fenix 5x Plus is also having open water issues.
  • Join the International Ice Swimming Association and embrace winter skins swimming!
  • Swim tracking with F5+ is not nearly as good with the 935. This morning's swim recorded with my wife's 935 is much better than that with the F5+. The 935 distance is the correct distance. The course is a 2000m track from the shore along a buoy line.
  • philipshambrook Would you mind reaching out to Garmin Support? We would like to get a few files from you from both devices and also have your permission to use you and your wife's data to look into this data. Plus, if you are able and willing, we would like to see what happens if you were both watches on the same arm and swam with it. That way both devices would have the same stroke timing in and out of the water. If you have any questions or comments, you know you can always reach out to me via PM.
  • Sorry to resurrect this but OWS just doesn't work for me......6.00/ 2.3... it gets GPS then the distance drifts like 300m each second when stationary. Anyone else seen this?
  • I have not had a chance to OWS since the GPS firmware updates that occurred late last year. Are you on GPS 2.3? I am currently running the 6.55 Beta and am on GPS 2.50. Where are you located? APAC?
  • Sorry to resurrect this but OWS just doesn't work for me......6.00/ 2.3... it gets GPS then the distance drifts like 300m each second when stationary. Anyone else seen this?


    The Fenix 5+ isn't stellar on open water swimming. It's a really hard thing to track. Watch the DC Rainmaker video "Openwater Swim Mega GPS Test // Garmin, Suunto, Polar, Apple, COROS"

    Spoiler alert: Everyone not called Apple is pretty bad at it. It's gotten better. Every open water swim I did with my 910xt was just horrendously bad, and now it's just pretty bad. Maybe because of the extreme smoothing that Apple does with its GPS tracks, it manages to give about the best results with the Series 4. I actually wish that my Wear OS watch did open water swimming, because it can use a sort of "Combo" GPS where it uses my phone for GPS when the watch's reception is bad, so I could just use a swim buoy with my phone strapped to it to improve the GPS track.

    I really wish Garmin would allow you to connect an external GPS device via bluetooth to improve GPS reception, it would solve the GPS reception issues caused by your arm dipping underwater while also counting your strokes, which you don't get if you strap your watch to the buoy. You could get BOTH. It would also improve GPS performance on other sports.
  • OWS swimming with the 5-plus is very much a work in progress; sometimes I get good results, more often than not they're a bit bleuggh! I think for the moment, if you want a good result you need to put the 5-plus under your swim hat. I'd have to agree that Apple do seem to be making a better go at it for OWS at the moment compared to the 5-plus. However, it's also clear whatever Garmin has done for the 935 in the open water is clearly working.

    I don't believe that's all down to the difference in construction material between the two either. It wasn't so long back that the 935 went 'berserk' in the water after the GPS change. It took a month or two, but Garmin fixed that up. I'm hopeful that Garmin will also be able to fix the 5-plus too. Although I've only got another month or two before I'll be following black lines again. Hopefully you folks down in the northern hemisphere will have an improved OWS record from the 5-plus when you get back into the open water.
  • Thanks for the replies but I think there is a more fundamental problem with mine. Other activities' GPS fine, but OWS drifts like crazy...it's 300m per sec !
  • I don't think yours is behaving any different to mine. Take this morning for instance. Started of fine but somewhere it lost the signal. When I stopped at a buoy it regained the signal then climbed from somewhere around 300m to over a 1000m in seconds - look at the straight line - https://connect.garmin.com/modern/activity/3415139166. It then sort of tracked back to the finish.