I placed my GPS unit on the back by the vent. I placed the ducer as a through the hull directly in front of the old ducer. If you dont have a unit you are upgrading from then you will need to bring power from the cranking battery. I would run shielded 14gauge wire from the battery to the source, I tied mine in between the console and the gunal on the right hand side, drilled a hole to bring the cables up through. Fishing the power source and transducer cable can be a PIA, and was the toughest part of the job