Could be difficult as Navman disappeared a couple of years ago by their parent compant
Navico, and replaced with Northstar, which again got kicked to the side and basically forgotten about, replaced this time by lowrance in their
marine catalogue in
Australia. There are no spare
parts available for them if you ring and they are not interested in them at all.
Northstar still lives i think but for road based
gps only.
Coops.