Hand held GPS
I have the 76S, which I think is more than adequate. It holds 25 MB of data, which in my case is the entire Chesapeake, five adjacent counties, and the topo maps for the northern Shenandoah Park area. If I need more, I can download and reload as needed.
The only downside is that it''s hard to read in direct sunlight. Since the bimini is usually deployed while under sail, direct sunlight is not usually a problem. YMMV.
~ Happy sails to you ~ _/) ~