The present invention relates to a start-protection system for an engine of a marine vessel. The engine has gears and a shift actuator for operatively shifting the gears. The system includes a first position sensor disposed to operatively sense whether the engine is in a forward, neutral or a reverse gear position. The first position sensor generates a signal representative of the gear position. The system includes a second position sensor adjacent to a shift control which controls shift functions of the engine. The second position sensor generates a signal representative of the position of the shift control. The system includes processing means. The processing means are configured to receive the signals of the position sensors, determine the gear position and the position of the shift control and enable the engine to start upon determining that both the shift control and the engine are in neutral positions.