In the altimeters options, under Auto Cal, you can select "continuous", "at start", or "off" under During Activity. You also have to select either "on" or "off" under Not During Activity. It's my assumption that if you select "on", the watch will periodically do an auto calibrate of the altimeter when not doing an activity. Am I correct, or did I post some bad info on another thread? :eek:
I found the answer in case I wasn't the only one unaware of this. If Not During Activity is set to on and if the watch is connected to your phone, it will use your phone location and calibrate using DEM while in your set sleep window.