A marine propulsion system comprising: a fuel-filled tank; an air compressor that generates compressed air; an engine that receives fuel from the tank, wherein the air compressor is powered by the engine; and at least one hot gas generator that receives compressed air from the air compressor, the hot gas generator comprising: (a) a combustion chamber having an inlet and an outlet, the compressed gas injected into the combustion chamber at the inlet, the combustion chamber adapted to produce hot gas; (b) an injection nozzle that receives fuel from the tank, the injection nozzle positioned proximate to the inlet of the combustion chamber, the injection nozzle adapted to spray the fuel into the combustion chamber; and (c) an exhaust nozzle positioned at the outlet of the combustion chamber through which the hot gas produced in the combustion chamber is discharged from the hot gas generator.