This idea belongs to a Dutch captain engineer, Mr. Ernst-Jan de Groot.
The magenta arrow indicates the direction of the boat's movement.
Input: green shaft.
The green worm is fixed to the green shaft.
Yellow worm has a prismatic joint with the green shaft.
Two blue double cranksets receive motion from the green shaft via worm gear drives and rotate in the same direction.
The pink foil has a revolution joint with the violet slider that moves along a vertical runway.
Two yellow connecting rods connect the blue cranks to the foil.
The angular offset between the blue double cranks determines the angle of attack of the foil.
The angle of attack can be adjusted by using the brown screw to move the yellow worm axially as shown in the last scenes of the video.
Reversing the input rotation causes the boat to move backward.

Inventor files of this video:
https://www.mediafire.com/file/qmtun4...