AVMAP
Hi WSPS
I used the AVMAP lll in the past found it to be quite good, could store 3000 way points on it, then another 3000 on each memory card you had for it, so it was good for things like pipe lines (Could store the whole of the line) I use to mount it on my leg like a knee board which worked well, had enough room and that was in a 22.
The only draw back was the batterys didn't last to long so you had to plug into the power supply. I don't know how the Avmap lV compares.
TTTE.