645 navigation features

I finally did some hiking with my 645. In case someone else comes across this, here is a summary of navigation in firmware 4.20.

You can save a location from the controls menu (long-pressing Light) and edit Name, Icon, Position (coordinates in degrees and decimal minutes), and Elevation.

Within an activity or the list of available activities, you access navigation features by long-pressing Up and selecting Navigation. Options (actionable items): Back to Start (Straight Line or TracBack), Courses (Do/Do in Reverse), Activities (Go or Back to Start), Saved Locations (Go To). I've omitted options for viewing or editing details, though you can edit all the attributes of a saved location here, too.

When following a course, these screens are added to your existing data screens: a breadcrumb-style map, bearing, an elevation profile, and a screen with fields for ETE, remaining distance, and ETA. (See also this post.) You can choose among quite a few navigation-specific fields for custom data screens: Dist. Remaining, Estimated Total Distance, VMG, Vert Spd to Tgt, Bearing, Course, Off Course, V Dist to Dest, Glide Ratio Dest., Location, Dest. Location, Lat/Lon, ETA, ETE, Dest. Wpt, Next Waypoint, Distance to Next, ETA at Next, Time to Next. (Punctuation seems a little inconsistent.)

You can also add a compass to the controls menu, widgets, or data screens, though there is no native ABC widget like on the 935 or Fenixes.

The 645 does not have Sight N Go, though you could edit the coordinates of a saved location and navigate to that point.

I haven't used a 935, though I reckon the sensors are the same and work similarly.

Can you can save locations with the 645 by holding down the top left button and choosing Save Location? YES
Can you load up the navigation options within an activity, such as a run or a walk? YES
Can I also get ETA / ETE in navigation mode during a walk? YES
How do I edit coordinates of a Saved Location? Before Starting Activity, Hold UP>Navigation>Saved-Locations>Position
Do the ABC sensors work just as well on the 645 as they do on the 935? YES

I finally did some hiking with my 645. In case someone else comes across this, here is a summary of navigation in firmware 4.20.

I've used the 645 a lot for hiking. It's a very capable navigation aid - just as good as a Fenix in this respect. I always save my current location at the start of a walk so that I can navigate back to it if I need to. It will get you out of trouble if you get lost in the mountains or get caught out in bad weather.

I downloaded a useful app called OS Grid Locations which brings back the ability to create British Grid waypoints, which was removed from the 645 by Garmin to boost sales of its more profitable Fenix range.