D2 Delta PX - GPS signal at high altitude

There have been mixed results using the D2 series watches in commercial flight decks, as seen in the threads I've listed below. The issue is not so much altitude but whether or not the design of the flight deck in question causes interference to reception of the incoming GNSS signals. In most cases this seems to be due to the heating elements embedded within the windscreen. I don't think there have been many reports of attempts to use the D2 Delta but there were a lot of reports of the D2 Charlie not working in various airliners unless you were a passenger. However, I think that Garmin has been good about accepting returns based on this but there's no guarantee. If you wanted to be sure I would call Garmin Aviation Support and ask about potentially returning the device if it failed to work as expected.

• https://forums.garmin.com/forum/on-the-trail/wrist-worn/d2-series/1281274-d2-charlie-gps-signal-airbus-320 (A320, MD11, B767)
  
• https://forums.garmin.com/forum/on-the-trail/wrist-worn/d2-series/1312355-d2-charlie-version-4-00?p=1313528#post1313528 (B747)
  
• https://forums.garmin.com/forum/on-the-trail/wrist-worn/d2-series/1312355-d2-charlie-version-4-00?p=1316333#post1316333 (HDJT)
  

As for whether the watch is a toy or a tool, that too likely depends on your situation (and/or your financial situation). If you have Internet access in-flight (and are allowed to use it) then you will have METAR/TAF, and in some locations NEXRAD, on your wrist. And you can potentially use the watch to help generate logbook entries for you (assuming you use the FlyGarmin website). If you are looking to get a smart watch and can make use of the other functionality on the watch for activity tracking (steps, hiking, swimming, etc) and want to have some aviation functionality then I would definitely recommend the D2 Delta, which I own and use in that manner. But if you are just looking for a "pilot's watch" (which in itself is defined differently by different people) then it becomes harder to recommend, especially if you are really wanting it only for "professional" use. That said, it might be moot if you can't get the GPS to work when flying.

As for the D2 Delta PX version, there is yet to be much feedback ][here in this forum as to how well the Pulse Ox works but since the D2 Delta PX is based on the Fenix 5X Plus and you can read about people's experiences with F5X+ in this forum: https://forums.garmin.com/forum/on-the-trail/wrist-worn/fenix-5x-plus

Thank you so much for your very valuable post, really appreciated !
I will read carefully the different links provided, then I will decide whether I go further or not in purchasing this watch.
Thanks again !

I had no problems getting a signal on my D2 Delta at high altitudes as a passenger. I flew to Kansas City yesterday on a 737 at about 35,000 ft sitting right above the wigs, it took a bit longer to lock in, but overall it worked fine.

Thank you for your feedback !
I think I will buy this watch on next week. Nice Christmas gift :p