1) Have 4 one touch buttons to change both screens to preconfigured situations,
2) Have a rotating knob to zoom in/out on the maps
3) Be able to change stuff on the screens while rested on the seat
4) ...have fun

(at the moment it is working on batteries, I still need to figure out how to pull a cable from this location to the helm-station or engine room and connect to the NMEA network.)