I have a Garmin GPSMAP 441 that I will be mounting on my 1979 Catalina 27. This unit has a 4 inch screen and will be powered by the boat's battery. I would like to place it on the port side rear rail. I steer by tiller so there is no wheel pedestal. I believe RAM Corp produces a bracket that will fit the rail. I'm looking for advice regarding the ideal mounting location. The unit will be removed when not in use so I am also looking for recommendations for runnning the wire and it's storage. The batteries are also located on the port side.