LR,

Thanks, that is the info I was looking for. I plan to get a new boat this fall and after searching, I've landed on Lowrance HDS Gen 3 units as the best buy (for the money) that will do what I want, which is to write the waypoints on both units. Last night I watched a couple of YouTube videos of some installs very close to what I want and it didn't look too complicated to do. I'm not familiar with NMEA networks but with proper instructions I think I can get it right. And the fact that one map card can be used saves some serious bucks that could be spent elsewhere.

By the way, what type transducers are you running on trolling motor and the stern?