Is it OK to use a Garmin Forerunner 310XT? I tested against  a GT31 in my car and found it to be within 0.1 to 0.3% of the GT-31.
Garmin say it is waterproof to 10m and is much easier to put on.
Steve: no, it isn't allowed. Check the Info and Rules section:

"hese are the devices which are allowed on

 Which GPS should I choose?

Recommend device:Navi GT31/ Navi GT11 / Amaryllo Triptracker

Allowed devices: Garmin- Edge, Geko, Foretrex, Forerunner and Etrex (legend and vista)

Testing Phase/ Trial: Velocitek (jan 2008)"

Ah.. Sorry, missed the Forerunner.. :)
Jesper - thanks I see it is OK. I wondered if anyone else had experience of using one and found if it really is waterproof. If it is then a lot easier than burying GT31 is pouches etc.
"I wondered if anyone else had experience of using one and found if it really is waterproof."

Yes, it really is waterproof, and I've taken mine windsurfing many times in conditions that have killed other Forerunner's I've owned.   That's what is so frustrating about the FR 310XT.  The form factor is nearly ideal for GPS Speed surfing, but the software it's running makes it almost useless.  Ignoring the lack of doppler data recording, the biggest problem is that there is no ability to set the track point recording interval; it's always on auto-interval (3-8 seconds).  The other problem being that Max Speed isn't a data field that can be displayed.   Most frustrating of all is that these two stupid-simple features have been on the two previous Forerunners that I've owned (the FR 305 & 201).   

Check that... Garmin added Max Speed as a data field in firmware version 3.00.

Thanks for messages on it is waterproof. Latest firmware does display max speed. I emailed asking if firmware developers could add in 1 sec interval and Doppler recording - if they can this will be great for windsurfers and speedsailors.


New Firmware (version 3.70) add the ability to record track points once every second:   

  • Added an every second recording option. The user no longer has to be paired with a power meter in order to get once per second recording. Go to Settings>System>Data Recording to enable.

And... a Max Speed field was added back in version 3.00.    There's still no Max Lap Speed, though. 

Note that some people are having some issues with version 3.70 of the firmware.   Check out the 310XT section on the Garmin Forums for details:


Next time we get some wind I'll compare to my Gt-31 :-)

I had a session and used 310XT and GT-31. Dislay max speeds were very close as were 10sec etc calculated by software. There was a 0.3knot difference in 1 sec max speed. Is that good enough to use 310XT reliably?