Unable to help on gps,but the manual you want is on the www.raymarine site.
3 versions of pdf files .
Two are the same thing and the third is a mini version of the previous two.
do what i did and download them all.Takes around 10 mins per version and you finally will know what all the knobs do!.
Mine system is not working as it should,so any info is useful.
<hr width=100% size=1>Two boats please one here n one in the Med