Unusable Distance/GPS Open Water Swim

I did this once with my 935 once for fun. Was as comical for the result as you expected. Not a long enough path before the flip. 

Thanks nord0296.
I went for 1.500m in the 50m outdoor pool (pre covid) and tracked this with a fenix 3HR and it was pretty accurate: https://connect.garmin.com/modern/activity/8944393433

Yesterday a 800m swim in the same pool with the 945LTE was not as accurate (613m) as the fenix: connect.garmin.com/.../9292337449

…Reset done, it helped….OWS looks fine now - seems really to shorten a bit (5-10%) - but that’s really ok…

 my 935 was perfect for OWS for years. My current 945LTE is structurally 20% short in any setting combination (satellite / recording smart or 1 s). This must be a software/algorithm issue as the recorded map is fine

Curious about that too, as I'm seeing a similar problem, but only 50-60% consistently.

Factory reset… now it‘s netter - in average 10%-15% short. Ironman distance last weekend e.g. showed 3491m - other recordings from friends  3750-3900

Interesting. Did a 2k swim yesterday, 3rd party app to test if this is related to the app itself, but got similar results. The workaround for me now is to download the GPX and hand edit the distance to match the actual distance. Of course this throws the pace off, but average pace and stroke rate are perfect then.

Since the distance comes from Garmin IQ, this might be a bug on Garmin server side, or at least with their measuring algorithm post-processing the watch sensor data. Note that there is also a stroke length setting for indoor swimming, maybe that is somehow related.

@maxh71: Exactly the same at me 10% short. I even got a replacement, no change  - so frustrating, no words from Garmin

@machinekoder: Strange my impression is that the watch is wrong. If I download the GPX the distance is correct. But importing GPX removes some of the specific swimming related like SWOLF and stroke rate.
What do you mean the distance comes from Garmin IQ? I only measure my outdoors swimming.