Method and system for fluke drive

A method for retrofitting a vessel with a fluke drive system, which method comprises the steps:

• providing to the vessel a pivot element having a forward end and an aft end and being connected at the aft end to a flexible fluke, including connecting the pivot element at the forward end to a hull of the vessel;
• providing a driving mechanism having a drive point, which driving mechanism is arranged to impart a reciprocal or rotary movement to the drive point;
• and
• providing a drive rod having a first end and a second end, including connecting the drive rod at the first end to the drive point and at the second end to the pivot element,
• wherein, in the said driving mechanism provision step, a carrier element is fastened to a propeller axle of the vessel so that it rotates with the said propeller axle, and wherein, in that, also in said driving mechanism provision step, the said drive point is eccentrically arranged on the carrier element so that a rotation of the propeller axle will drive the drive rod back and forth, in turn resulting in a reciprocal up and down motion of the flexible fluke, and wherein that the second end is connected to the pivot element at a point along the pivot element between said forward and aft ends, and in that the pivot element is arranged in its entirety externally to said hull and pivotally connected to a pivot point which is welded to the said hull.