Garmin D2 Air X15 Aviator Smartwatch: Slate with Black Silicone Band

I have only had this watch for a week. This is my second Garmin watch and this one is quite impressive. My only complaint so far is it sometimes goes into other modes, like countdown timer without my input - I suspect from it jostling around on my wrist, but IIRC there is a 'lock' mode to prevent this. Heart rate, altitude and SP02 readings are beneficial as a pilot and as high elevation backpacker.