join the club shine runner i have a 727 i was trying to hook up a etrex hand held .humminbird sent me the cables thay said would work but didnt when i contacted them thay said thay were trouble shooting the promblem as we were speaking so i asked were did that leave me long story short thay sent me a gps receiver free of charge which i thought was pretty good on their part but that still leaves the question how the hell do you hook up a hand held to the 700 series let me know if you have any luck