Abstract: A trolling motor system is disclosed. The trolling motor system includes a lower propulsion unit, a mounting mechanism adapted to be coupled to the boat and a first shaft fitting at least partially between the mounting mechanism and the lower propulsion unit. The first shaft has a non-circular cross-sectional shape. In one exemplary embodiment, the mounting mechanism is configured to mount to a boat having a longitudinal axis extending from a bow to a stern of the boat, wherein the first shaft has a longitudinal length and smaller transverse width. According to another exemplary embodiment, the first shaft has a hollow interior which receives a second shaft. A passageway is formed between the exterior of the first shaft and the exterior of the second shaft to receive the signal or power transmitting line of an underwater sonar system.