Abstract: An adjustably mounted side rigger for use on a fishing boat that tends fishing line from a fishing rod outward from the boat during trolling. The side rigger extends a fishing line to the side of the boat during trolling in order to prevent the line from entangling with other trolling lines originating from the boat. The side rigger contains a rod holder base adapted to fit inside an existing rod holder on a fishing boat for portability, flexibility of use, and lower cost than a traditional outrigger. The rod holder base and a telescoping pole mounted to the side rigger that extends the fishing line outward from the boat, are both adapted to be rotated or swiveled by a user to allow the side rigger to be used on either side of the boat and used in a variety of different angled and positioned fishing boat rod holders for maximum flexibility.