Hi, it seems I'm losing data on my GT 31. Almost each session ends up being 4h30m while most of the time I'm on the water longer than that. Today as well, I had 147.9 km on display for distance, and GPS logging only shows 120 km. Anyone has an idea how to solve this?

I was already thinking about starting a new session on the middle of the day and joining them later on.

Any idea would be appreciated.

Please check your card if you have multiple SBN files.

Also compare against the datalogger. Just save the data to the card and check the SBP file.

The same problem overhere, losing data in the middle of the tracks. .

card has multiple SBN files , saved the data to the card, but i can´t find any SBP file .

Maybe the most essential question: when I use GPSResults to download the data from my GPS, does it only download the GPS internal memory or does it actually take data from the SD card?

The setting should be card size at the memory card menu.

Also set the minimum speed to zero/off so you can check if something went wrong.


I had mine set to 3 km/h. I will change that and see what happens next session.

Resolved by downloading data from SD card instead of using the download via the USB cable. Thanks for helping!