Hydraulic outboard steering is an option offered on power boats. This system uses a hydraulic cylinder attached to the outboard motor and allows the operator to steer the boat with less effort. The hydraulic outboard steering uses the hydraulic cylinder's ram to push and pull on the outboard in conjunction with the turning of the boat's steering wheel. Much like power steering in an automobile, hydraulic outboard steering makes turning the motor from side to side a very easy task. The torque applied to the steering action of a power boat is tremendous, and without hydraulic outboard steering, turning a boat or just maintaining a straight line would be nearly impossible at full throttle.
Boats using small outboard motors of less than 50 horsepower can operate without hydraulic outboard steering. Many of these boats are even tiller-equipped, meaning that they have no steering wheel. With outboard motors larger than 50 horsepower, hydraulic outboard steering is mandatory. Older boats used a system of cables and pulleys that allowed the operator to have a mechanical advantage when turning the big outboard motors. Modern boats use the hydraulic system, which is typically operated off of an electric hydraulic pump motor.
Much in the same manner hydraulic tilt and trim features have replaced the manual systems, hydraulic outboard steering has replaced the older system of pulleys and cables for turning the large outboard motors. Even with the pulley and cable system's use of leverage, the hydraulic cylinder-assisted turning mechanism allows for a much smoother and easier turn. In multiple outboard configurations, the hydraulic outboard steering is a must. The torque steer produced by twin outboard motor set-ups makes any type of steering other than hydraulically-assisted steering futile at best.
In a twin outboard configuration, two equally-sized outboard motors are teamed together to achieve greater power potential. While this type of configuration will typically pair outboard motors with opposite-turning propellers to equalize the torque steer that the engines will produce, hydraulic outboard steering aids the operator in turning the big outboards as they power through the water. As with a single outboard configuration, the hydraulic steering also makes the task of holding the vessel on a straight line a much easier one.
The use of an electric hydraulic pump to power the hydraulic steering makes turning a kick motor with the boat's steering wheel possible with the primary outboard turned off. A kicker motor is a smaller outboard motor used primarily for trolling on a fishing boat. These small outboards are usually 20 horsepower and less and are typically linked to the main outboard motor through the use of a steering rod. As the large motor is turned, the steering rod acts like a tie rod on an automobile and turns the kick motor as well.