Im not certain about the units themselves drawing but I know my Lowrance recommended putting an on/off switch on the antennae wire, so I assume the gps puck has a draw of some kind even when the unit is powered off. BUT…..I know what happens when you “assume”. This is speaking about Lowrance but again I would assume they are all alike…… http://www.idofishing.com/forum/showfla … h-finder-s Last edited by toledobasser on August 8th, 2012, 11:55 pm, edited 1 time in total.Jim EbarbMany, LA (Toledo Bend Lake)2004 Cougar/ 225 OptimaxHumminbird Helix 12 Chirp SI on BalzOut Mount at bowLowrance HDS 7 at bowHumminbird Helix 12 Mega SI on Ram Mount at ConsoleLowrance HDS 8 in dash at console