In reply to finnegankp:
> And while maps aren't exceedingly expensive and range between £9-15 each, they can only cover so much of an area
About that - if you have a printer, especially an A3 printer, this might be worth a look:
https://www.ordnancesurvey.co.uk/shop/os-maps-online.html
https://osmaps.ordnancesurvey.co.uk
I print and laminate my own OS maps (to scale) for sea kayaking, and have a growing pile of handy little waterproof maps that I can scribble temporary (but waterproof) notes on with a chinagraph pencil. It's brilliant - well worth 20 quid a year to me.
> So while I appreciate the suggestions and being clever, we really were just hoping to find a good samaritan that might help us recover the GPS.
There were always going to be some smart comments about how you don't need GPS, and some (imo) wise council that you should really have a paper map as well even if you do have the GPS.
If these posts are getting you down, don't lose heart. Each post is also a bump that makes it a bit more likely (or given what you're asking for perhaps I should say a bit less unlikely) that someone who can help you out will see your thread.