Open Water Swim performance

Weird that it does that.

I received a replacement 945LTE as support wanted to swap mine out to see if any of the minor issues I had seen with the first would be resolved.  I did my first swim with the replacement today and the tracking looks good, distance seems within about 6.5% of my buoy reference and the FIT file did not have a weird distance offset (and Strava was mostly happy with the file as well).

Connect: 2136 yds, Strava 2283 yds, Buoy Reference: 1998 yds

I'll see if a follow-on swim shows causes the weird sync and FIT file data...

Does anyone know if the GPS chipset on the 945LTE is different from the standard 945?  I also wonder if the good swim results that you are seeing are an improvement from the 945 or pretty much the same.  If the HW didn't change with regard to the GPS chipset that either the performance between 945 and 945LTE is the same or they improved SW or antenna or something got improved.  I have the Fenix 6X Pro but have severe GPS issues during OWS.  FIT file shows GPS signal is only available less than 10% of my swim time so I am curious if the 945LTE is doing something completely new and improved that perhaps the rest of the watches would benefit from soon, ie Fenix 7.

I saw speculation that it may be a different chip (but by a minor revision rather than a whole new generation or vendor).  I don't think anyone has confirmed anything.

Your experience sounds frustrating.  My wife has a fenix 6s and her swim activities seem to roughly align with what I am seeing now with the 945 LTE (I previously had the 935 so no personal experience in between).  She doesn't bring a redundant GPS in her buoy and analyze it quite like me but her plotted tracks look believable and notably better than I was seeing with my 935 in mostly similar uses.

My guess is the 945LTE isn't that different than the fenix 6 series (so nothing dramatic in algorithm or chipset) but I have no real information on this except a personal guess.

Just looking at the track result, I am pretty sure that 945 (and Fenix6) and 945LTE has the exact same algorithm for OW swim. I have Swim2, what is similar to 945 for OW performance, and GPS chipset.

Earlier I had lots of problems with GPS signal loss, but it turned out that using my other wrist makes miracle. I think that it is just about swimming style. The new algorithm seems to be much much more accurate, but less robust, so some special swimming styles might cause problem (I have slow stroke rate, that is definitely something what the new algorithm does not like).

To be honest, the OW GPS performance seems to be better, than the running performance...

i think i agree that some improvements were made with the alg and that if i wear it on my right hand its better (when i breathe to my lefft). However, since i swim along the shore line and i prefer to see the shore when I swim, i breathe to the left one way, and to the right the other way. So for me, regardless of which hand i put the watch on, one way is better than the other. What bothers me is that with the 910xt, f3 and i think f5 (less ows on f5) i never had such issues.

Had a swim today and got a similar problem.   Garmin trace says 1509 yds, which is reasonable

connect.garmin.com/.../7031906259

Strava says 11k 

strava.app.link/LPk3CN2grhb

Open water has been a disaster on my new 945 LTE.  It is telling me a distance and pace about 40-50% off from the 735XT I wear on the other wrist.  735XT GPS is super accurate on my known swim distances and has been great in all activities over the years.  What's bizarre is when I download both tracks into course analyzers or Google Earth both watches have similar tracks and distances!  This morning I swam 3,000 yards per my 735XT and downloaded tracks on both 945LTE and 735XT but on the Garmin Connect activity (and on my 945LTE) is says the swim was only 2,269 yards with an absolutely horrific pace.  I've tried both GPS + GLONASS and Galileo with similar results.  Both watches are set to "Smart" data recording.  Thoughts?

See my  post (link below) I and others are having similar issues with the Fenix 6. I think I see why it ends up being short and hoping Garmin can still improve this with SW.  Bottom line is I think the new watches use a different GPS chip which, with regard to OWS is not working as well as prior chips, off course they are much improved in terms of battery consumption.

forums.garmin.com/.../garmin-i-think-i-see-why-some-users-are-short-on-distance-during-ows

after further investigation, the "moving time" seems to be the issue.  My "moving time" on my 945LTE is 12 minutes less than my elapsed time and 9 minutes less than moving time on my older 735XT. It was a continuous swim.  Yet the courses on both per GPX file is exactly the same at 3,000 yards.  It seems to be assuming if there is no GPS signal I'm not moving and then I magically appear somewhere else!  Quite insane!

I thought you said the 945 had less distance, ie 2269 yards but above you mention that GPX files show 3000 yards?  With regard to less time, yes, I think it basically translates to those 12 or so minutes is how long the watch didnt have GPS signal during your swim and therefore, I guess with regard to time is assuming you didnt move.