I'm mainly using my watch for recording runs. I click on the Run activity and wait until it says GPS READY. Then I press the top button and run.
I'm not looking at the watch at that point, and always feel it vibrate after about 10 seconds. I think that up to that point it has recorded time but not distance. My first 1km is usually the slowest.
I did experiment by looking immediately down at the watch face, and it had a yellow border. Is this an indication that it has lost its GPS lock, or some kind of count down timer?
Thanks