I have a PA-14 and a Canon Mini-troll.......takes the same area to mount a Scotty Lake troll......I located mine on the left side....since I used Scotty flush mounts, the lake troll and rod holder can be plugged into either receptacle/socket. The white line on the down rigger is a safety leash.
Having owned both a smaller Scotty and Canon, of the two, I liked the Canon as it has the line counter....that's a feature missing on the Scotty.....unless you upgrade to the Scotty Depthmaster Model 1050....that is a much better downrigger and I am in the process of making this change/upgrade.