Hi
I have a Garmin 645. The GPS works well and is accurate for cycling & walking/running, but does bizarre things when I use it for open water swimming. Today I used it and stopped my session when I had reached 2500 metres as indicated on the clock face. However when my swim was saved to Garmin Connect and Strava it showed a completely different distance of over 3900 metres. The time and the map tracking were accurate and consistent with a 2.5k, but not the distance saved. Can you offer any explanations for this and how I correct the situation? ps I checked before setting off that the GPS was indicating ready.