Disclosed herein is an inboard-outboard driving mechanism for a boat having a hull, the driving mechanism including a support adapted to be fixed relative to the boat hull, an engine mounted on of the support, a propulsion leg including a rotatably mounted propeller, and structure for connecting the propulsion leg to the support for pivotal steering movement about a steering axis. The inboard-outboard driving mechanism also includes apparatus for causing pivotal steering movement of the propulsion leg including a steering shaft rotatably journaled in the support, and gearing connecting the steering shaft and the propulsion leg for pivoting the propulsion leg in response to rotation of the steering shaft. The steering shaft is selectively rotated by a lever mounted on the engine for pivotal movement and having opposite ends, one of the ends being connected through a gear box to the steering shaft. A fluid motor mounted on the engine is connected to the other end of the lever, and the fluid motor is actuated by a fluid valve. The fluid valve is in turn actuated by movement of a conduit of a steering cable. The steering cable core is also connected through a rigid link to the lever for assisting pivotal movement of the lever.