Abstract: A trolling brake for a motor powered boat to enable the boat to move at varying slow speeds while the motor is running at idle without stalling the motor. The trolling brake is formed of a semicircular shield having a pair of forward ends pivotably mounted on the transom of the boat at or near the waterline and an adjustable support pivotably mounted at a rear portion of the shield and to the transom of the boat for adjusting the position of the shield in the water. The bottom edge of the shield slopes downwardly and rearwardly from the ends to a rear central portion and the shield has a pair of holes equidistant from the centerline of shield rear central portion to permit the passage of a controlled amount of water through the shield to facilitate steering of the boat with the shield in operative position. The center of curvature of the shield is substantially at the pivot point of the out-drive portion of an inboard-outboard motor and at the center of the craft when the boat has an inboard motor or motors.