FR945 swim map vs swim distance (GPS Issue)

We’ve been swimming with ours until recently without problems. It’s been over a month since the last swim so possible recent updates have caused a change. However, restrictions ease here tomorrow and we’re planning a sea swim. I’ll try to remember to post  the results.

cool looking forward to it!

where are you actually?

Finally back in the water now that the lockdown restrictions have been eased allowing us to swim. Comparison here between 945 and Instinct. Broadly in the same area and distance ~1000m as expected. We have a buoyed swim course marked with buoys at ~250m intervals - out and back to the second buoy is then ~1000m. Between the two watches only 50m difference. 945 was connected to a HRM-Tri but not the Instinct

Thanks for the test and report. Good to know that there is no general issue.

What GPS settings do you use? (GPS only, GPS+GLONASS or GPS+GALILEO)

Do you have automatic sync set with the phone? Are the watches always on? Do you sync time with GPS? Do you have a special routine with the watch before each OW swim?

I suspect that the watch relies too much on the phone, and if phone sync is not frequent, some data might be missing, causing frequent GPS loss and too slow GPS lock. (my watch is mostly off, I switch it on only before the swim, and phone sync was off, as during swim the constant BT search used too much battery earlier)

My planned routine before next OW swim will be the following:

- renew CPE file at home

- at arrival, sync with the phone several times (location on on the phone)

- GPS lock for some minutes

- sync time with GPS

- start recording, wait another 30 sec for even better GPS lock

If that does not help, it will be a clear indication of hardware issue. I hope that this routine will make the trick

GPS+GLONASS, automatic sync with phone but then I’ve also swam with the phone left at home. My watch is always on and always connected to the phone when the phone is nearby. The most I’ll do occasionally is close GCM on the phone but that’s not that often.

I don’t do anything special before getting in the water.Select the Open Water swim activity while getting changed so it’s got about 5 minutes or more getting a lock, then just  wander down to the water, press start and swim.

It is possible that your CPE file gets out of date in between syncs to the phone. How often do you sync with Garmin Express? WHy do you feel you need to turn your watch off? 

Thanks. So frequent sync with the phone should make the trick. Usually I do not sync with Garmin Express, but from now I will do it regularly.

I switch off the watch between swims because I use a regular watch, I do not like any smartwatch for everyday use. I do not want the watch to sit on my desk switched on for days. 

PG said:

I do not want the watch to sit on my desk switched on for days. 

No problem there but if there are days between swims it might be worthwhile turning it on and allowing it to sync with at least your smartphone for a few hours beforehand.

The Instinct used in the swim the other day is not synced to any smartphone but was synced/updated with GE a day or two before.

I made a swim test again, with catastrophic results.

I switched on the watch hours before. I downloaded a fresh CPE file, made several sync with the phone, here at home and at the beach. During the change it was waiting for an even better GPS lock. Synced time to GPS. Waited a bit before start, after I started the recording. Started to swim. Bright open sky, no clouds.

And

The watch IMMEDIATELY lost GPS signal (now GPS+GALILEO but I tried the other options earlier). It made a track just because I stopped several times to check. Old FR910XT recorded the track perfectly. 

Here is the Swim2 track (4171 meter...)

and here the FR910XT (the track is completely accurate, 2480 meter)

Now I put the watch outside without any move for 50 minutes GPS recording to have a long GPS soak. If that does not help, the watch goes back to Garmin for a replacement.

It is Swim2, not FR945, but as far as I know, same GPS chip, and there are problems with 945 as well.

Quality control?

Please don't take this the wrong way but if you are having Swim2 issues you are better off posting in that thread. Posting poor performance issues with the Swim 2 here will lead to people getting confused (and some will get very agitated) and thinking the issue is with the 945 The watches might have similar internals but that does not mean they will produce similar results. This was a swim this morning. The start was a bit offshore as I had some button pressing issues (user error) but the track is fine.

Of course that's not to say problems do not exist. I too have had some pretty dire results after software update particularly but in the main the results are more than acceptable.