Pedestal seats give you the advantage of having a seat, but not being stuck with a seat that points in the wrong direction all the time, since a pedestal seat turns. The pedestal takes up less deck space than the box-type seating you see so often and can be installed in tighter spaces. Installation is as simple as drilling a hole and turning a few screws.
Check to see what is beneath your proposed seat location; you don't want to drill into a fuel tank or through your boat's wiring harness. If the deck is covered with vinyl flooring or carpet, you must remove the vinyl or carpet where the seat base will be located.
Use a 3-1/4 inch hole saw on an electric drill with a stop gauge to drill the hole where the center of the seat's base plate will set on the deck.
Set the base plate of the pedestal seat in place. If the deck you are mounting your seat to is wood, use the 1 inch stainless steel oval head wood wood screws to attach the base to the deck.
If your deck is fiberglass, you should use rivnuts--blind fasteners--backed by large aluminum washers on the underside of the deck. Use the base plate as a template to drill the the screw holes. Lift the base plate out of the way and use the hole in the deck to insert washers and rivnuts, then set the base plate in place and attach with the screws supplied with the seat.
Set the pedestal and seat on the base plate.