So, I was trying on various Garmin watch devices, mainly due to the fact that I ordered a 305 online and had to return it because it just didn’t work for me. It banged into my very prominent wrist bone (outside of wrist, closest to pinky finger) and I was unable to tolerate it for even 2 miles of running. I ended up carrying it in my hand.
At the store, I was trying on the 310xt, and the FR 210, and both seemed like they would still give me this problem. Then the sales girl suggested I try the watch with the face on the inside of my wrist to avoid the issue.
I tried it in the store and it seems like it would work.
I have the exact same issue with the 310xt. Interestingly enough, became more difficult to tolerate after installing the quick release kit.
At first I tried wearing it on the inside of my wrist and that worked to relieve the discomfort; however, it felt too awkward to look at the screen when wearing it like that.
Best fix: wear it overtop of a wrist sweatband. The wristband adequately pads that bony prominence so that you can wear the watch on top of the wrist as intended.
I also have a prominent wrist bone so I wear a wrist/sweat band under the watch and find it provides enough of a cushion that I don’t notice the watch while wearing it. Give that a try perhaps?
The quick release kit for the 305 has a velcro armband. That was the most comfortable for me, because I could strap it rather tightly to a different part of my wrist, farther away from my wrist bone, and it wouldn’t hurt. I wish the 310 had a velcro arm band!
Now that I have a 310xt, I haven’t quite figured out how to make it comfortable yet. I’m hoping that if I keep wearing it, it will get better, but that hasn’t happened yet.