A system and method for combined control of steering and trim of a marine engine unit. The system and method includes a steering apparatus generating steering signals, a trim control generating trim signals, an electronic unit receiving steering trim and cylinder position signals and sending output signals. A port hydraulic cylinder and a starboard hydraulic cylinder that extend and retract are included. The cylinders connected to first and second port and starboard joints to provide movement of the engine unit. The first and second port and starboard joints enable movement of the engine unit vertically and horizontally when the port and starboard hydraulic cylinders are extended and retracted to provide a full range of steering and trim movement of an engine unit using only two hydraulic cylinders.