Huge GPS drift at end of open water swim?

Sorry if this has been discussed but I can’t find a thread on it

Today I swam in the sea, about 700m along the shore and back and I read about 600m before swimming a bit more to where I wanted to land. Then as I was getting out suddenly my F5 was vibrating with 500m lap counts one after the other, the activity looks like I suddenly swam a couple of miles on land! Anybody else had this or know what causes it? I went for a run a couple of hours later and that seemed to track fine. Also have done this swim many times without issue Any advice? I am running 6.0

This is the activity

https://connect.garmin.com/modern/activity/2135317561
(I edited the distance)
Thanks!

Top Replies

Former Member over 7 years ago +1

Hello:

The same happened to me. After a 10K swim and when arriving to destination I got a buzz in the Watch. I checked it and everything seemed de ok. Dial was showing distance and time.

But it was not…

All Replies

0 Garmin_ODQA over 7 years ago

Hi frogbmth, will you check the data recording method for your device? Settings - System - Data recording. For open water swimming, you will probably want the watch to be set to "every second." The "smart" recording works best for land activities.

0 frogbmth over 7 years ago

Thanks for the reply, yes I just checked and it is set to every second. Today’s swim was recorded correctly so may be was just a one off, here’s hoping :-)

0 NickCroken over 7 years ago

I'd also run glosnos as well as normal gps, I found that helped my open water swim accuracy.

0 frogbmth over 7 years ago

Thanks Nick will give it a try

0 Andy275 over 7 years ago

Did you swim any breast stroke? Or stop and tread water at the turn around point? The device can only register the GPS when it is above water. Although mine can pick it up fairly quickly, I have friends that lost their signal treading water and then, perhaps bc their stroke was too quick, it was not recovered. In your case perhaps it was lost and then the watch figured out the distance once re-acquired on land.

0 Former Member over 7 years ago

Hello:

The same happened to me. After a 10K swim and when arriving to destination I got a buzz in the Watch. I checked it and everything seemed de ok. Dial was showing distance and time.

But it was not true.

The arrival point was supposed to be exactly the same as the departure (an specific spot in a marina) but when I checked the final track there was a difference of 600 m.

On the other hand 600 m of my swim were missing.

Interestingly Strava acknowledged the missing 600 but kept the mistake on the arrival.

My settings were GPS GLONASS, registering every second .

Moreover I experienced lots of problems with the bluetooth connectivity to the Garmin app using an iPhone 6s Plus. I has to pair es three for times.

I have a Fenix 3 and in the past I owned a 910XT.

I still use the Fenix 3 for open water swimming.

i returned the Fenix 5.

I hope that they fix the GPS problems that the Fenix 5 still has.

Regards

0 frogbmth over 7 years ago

Interestingly I have never had this happen doing breaststroke, the track just looks more jagged which I expect but it has not shown this type of drift over miles of land. It happened again this week, using both gps and glonass at the start of the swim and then it settled. I had left the watch a few minutes after green ring signal lock too.
https://connect.garmin.com/modern/activity/2196082705

so I have done a master reset and my swim yesterday was flawless.
https://connect.garmin.com/modern/activity/2214714730

I guess only time will tell if it resolves the problem.