To be expanded!
(This is all in need of updating)
I have a Garmin eTrex H, one of the tough old yellow ones. It's the entry level one I could afford that ticked all the boxes for getting started. It connects to a laptop I have running Ubuntu via an old serial port.
How I operate
I'm still working that all out.
I'm drafting an inventory for mapping expeditions. It's been moved to its own article in my user area now.