In reply to jimfandango:
I’ve got a Garmin 735xt and it doesn’t have OS maps, you have to plot the route before or upload a gpx file, then you just have a line to follow in a blank space on the watch. However, this is more than enough to follow easily in any weather for me. I even sometimes put the watch on top of my coat sleeve if it’s really bad weather.
Although I want to upgrade to the latest Fenix 6 with the maps, I don’t think you “need” more than what my current watch offers.
I bet you could pick one of mine up secondhand for under a ton.
Also - ViewRanger on a phone is vastly superior, if you want a nosey around an actual map. I’m sure any half recent phone in a waterproof case would be fine enough. But not quite as quick and easy as looking at an arrow on your wrist.