A drive method is disclosed. An embodiment includes an operation of at least one drive propeller of the drive system below a first predefinable propeller rotational speed according to a first operating state by operating at least one drive motor, connected to the at least one drive propeller, of the drive system via a first alternating voltage. The method further includes operation of the at least one drive propeller above the first predefinable propeller rotational speed according to a second operating state by operating the at least one drive motor via a second alternating voltage. In a transition from the first operating state into the second operating state or vice versa, the first internal combustion engine is operated at such a rotational speed that the at least one drive propeller is driven at the first propeller rotational speed, and the first alternating voltage is synchronized with the second alternating voltage.