I have two units (2005 332C and 2007 27C), but cannot help right now because they use different connectors for the LowranceNet (Lowrance for the 05 and micro-c for the 07). The adapter I need to hook the two together was not available the last time I checked in February.
You should be able to share the waypoints over the net. There is a check box you need to activate in one of the menus. Maps are tied directly to a particular memory card and probably can't be shared over the net.
Currently, I have solved the issue by keeping the same data on two cards.
Keith
2008 NWR Bash Crappie Champion
2010 NWR Bash Yellow Perch Champion
2010 Buggs Bash Smallest Crappie Award