by StevieC » Tue Oct 17, 2017 2:34 pm
I use a Garmin GPSMap 64 which came with OS 1:50k and I never had any issues with losing resolution as I zoomed in.
I'm using the past tense because unfortunately I lost the micro SD card that the mapping was stored on - presumably while I was changing batteries out on the hills somewhere. I still use the unit for recording walks but I miss the mapping, even though I always have the "real" map in the backpack just in case.