i have a portable xm head unit,then you can buy the docking stations and put one in your truck,car,boat,house and then when you get to the dock,take the head unit out of your truck and plug it into the docking unit in your boat and you are good to go.if you are going to replace the stereo in your boat,get one with a rca jack in the front,then all you need is a rca cable to connect docking station to stereo.i bought the complete kits that come with the docking station and antenna on ebay for about 15 bucks a piece.