Fenix 6s Open Water Swimming under reporting distance & pace

I confirm that 17.72 and 5.30 GPS firmware make no difference...

i tried both, left and right. for me it seems that the watch prefers to be on the hand opposite my breathing side. Just did my first ows for the season and i at least see an improvement in the algorithm side. It no longer double dips and does its best to maintain distance measurements in the absense of good gps signal. So, with phone in buoy clocking in 1900 yards, the f6x pro ended up with 1600 yards. Again, to me the root cause is the poor gps signal (and Phillip) this is based on my swim style, etc because i never had this issue with the 910xt, f3 and f5. with the f6 my tracks are straight line (which can be half mile long or longer) which indicates no gps points (confirmed with fit file decoders) while tracks from prior watches were squigly, rounded, etc indicating gps points were acquired. 

When a device initially displays that GPS is ready, it means that the device has picked up the minimum amount of satellites needed to get your location. Waiting a few moments after your device finds a signal will allow additional time to communicate with satellites before you start moving for your activity. This practice allows for your device to communicate to additional satellites, creating a stronger bond and helping to reduce degradation of GPS signal.

regarding the above than perhaps Garmin should not give the gps acquired, all good signal until more sat are connected for ows.

How long and how many satellites is overkill? I'm sure there is a certain algorithm where  'X' number of satellites is adequate for 'Y' percentage of case scenarios.  If I had to guess, I think that 'Y" percentage is close to 99. I can't think of the last time I started an activity where the GPS data was off, after being given the green light.  

I have the same issue. In October 2020 I have noticed the sudden and very noticeable (25% - 30%) dip in my open water swimming speed reported by my Phenix 6. Please note, I have not changed the watch. At the time I thought that it was due to a two week brake. (Normally I swim 2 to 5 km almost every day). But despite of my trying to approach my August performance, I could not. This year, the same story, to average 2min per 100m pace on 2 km distance is impossible. I am very far from it - 2m40sec - 2m.50sec per 100m. Last summer I sometimes did 5km with average pace of 1m 40sec per 100m.  I was suspecting it then, but now I know it for sure. It was not me , it was and is the distance and pace calculating mistake that, most probably, came with a software update. How do I know it for sure? Thanks to Navigation screens you can add to your regular open water swim data screens while you are swimming. For me it is often important to get on shore on time, so I turn on Navigation to see a straight line distance to the starting point. This distance MUST be less than a distance I swam, at the best it can be the same. BUT the strait line distance as per Navigation screen was actually about 25%-30% GREATER than the total distance I swam as per Open Water Swimming screen . I have repeated this expriment 3 days in a row and the result was the same.

It is a clear and irrefutable evidence of distance calculating mistake! I will try to make some pictures of my Phenix 6 screen during my today swim, to illustrate my point. We should unite our effort to press Garmin to change this mistake. All they have to do is to roll back to the calculating method they used last summer  (2020) and earlier.           

Same here. Swam two measured 1500m rounds (measured and set with bouys) last week. So 3000m and I was swimming wide around the bouys and not all straight. So in fact it would be even more than 3000m. My Fenix 6 recorded 2800m. A friend swimming along side me had 3200m on his Fenix 3….

Hello Garmin: Just fix it!

I keep chiming in only with the hope that it makes up to Garmin's radar. I too have these issues and I never had these issues with prior Garmin watches.  Using the FIT decoders tells the story but the bottom line is that his GPS chipset doesn't perform as well as other chips used on prior watches.  The difference is marginal so unfortunately only a subset is affected and we are it.  I now have to wear the watch on my right hand if I plan to breath on my left (never had to do that with F3, F5 or the 910xt).  Even while wearing the watch on my right side, looking at the FIT decoders it still loses GPS signal every few minutes for a very brief period of a few seconds.  But for those seconds the watch essentially doesn't calculate distance properly so we end up with a shorter distance. Hoping there is still some hope that Garmin will be able to resolve this but not holding my breath.

Adding to my yesterday post. Attached is hard evidence of a very significant open water swimming distance & pace under reporting by Phenix6.  1^st screenshot - Garmin connect app map of my swim. 2nd Screenshot - I clicked on circle number 7 (info about my 7^th 100m lap), please note little Google Maps icon in the bottom right corner, when clicked it opened Google Maps app showing coordinates of my 7^th lap end (3^rd screenshot). Now, using Measure Distance tool (4^th screenshot), I measured the straight line distance from the end of my swim 7^th lap to the starting point. As you can see on 5^th screenshot, the result is 869 m!!! Thus according to my Penix6 after swimming 7 100m laps, I found myself 869 m from the point of my start. Please note, that I swam not in a straight line, far from it! So the distance I actually swam is no less than 900m, and NOT 700m! If you noticed or even just suspected distance & pace under reporting, could you please perform the same check on any of your open-water swim reports in Garmin Connect App, and post it in this thread. It would be the best way to make this very significant mistake evident for Garmin and hopefully make them to take action. 

Sorry, I could not master inserting images here. All screenshots are in this link : screenshots

I did every kind of test and reported all this to beta team since 1 year... nothing changed.

I will wright to them as well. What email have you used? Have they ever responded? Maybe there are other channels? Hopefully, if we are numerous and persistent enough they will act.