[chumbucket]

Why not just attach a piece of Starboard Permanently to the back of the seat with a couple of standoffs. The piece should be the same size and shape of the splashboard you currently have the rod holders on. When you slide the splashboard out to install the seat, the seat with Starboard attached will slide into the same tracks in it's place. That should keep the seat from sliding on you. You can also use pieces of pipe insulation on the base at the floor to prevent any marking of your deck. 8)