A steering sensor system is provided for a marine vessel in which a rotational position sensor is attached to a guide member that rotates about the central axis of the rotor of the rotational position sensor. A pin is attached to a moveable portion of the steering actuator and slidably disposed within a slot formed in the guide member. The pin is slidably within the slot as the moveable portion of the steering actuator moves along an acuate path that does not have the same center of rotation as the rotation of the rotatable portion of the rotational position sensor. The sliding of the pin within the slot of the guide member accommodates these different radii of curvature.