To fit the footrests in a boat, first work out where you want to fit them. On the outside of the boat, mark where you want the closest bolt to go through the hull. Place a bit of masking tape over the spot to steady the drill and using the correct bit size for the bolt drill through.
Using the footrest as a template, mark out where you want the second hole and repeat the procedure. Place the foam rubber washers on the inside of the holes and bolt the footrest through.
Footrests need to be relatively grit free to work well so it is advisable to rinse them out every now and again.