I have an older eastside drifter that has wooden side rails, I made a U shaped bracket out of 1in. round stock pipe, then flattened the ends and bolted it to the in side of the rails. Then I put on a pole holder bracket so the holder can be removed when there isn't a third person or your not pulling three plugs. If your boat is glass or aluminum this will also work, you should re-enforce the mounting area with a block of wood or some type of thick glass material for support.