Abstract: A method and an assembly are provided for mounting a pair of hydrofoils to an outboard engine without drilling holes or otherwise defacing the anticavitation plate of the engine. The assembly includes a mounting plate, an adaptor, and a pair of hydrofoils. The hydrofoils are mountable to the outer edge portions of the mounting plate. In use, the counter-rotation tab of the engine is removed and then replaced by the adaptor. The mounting plate, if not already secured to the adaptor, is coupled to the adaptor. The hydrofoils are then mounted to the opposing edges of the mounting plate. A pair of reinforcing brackets may be secured to the mounting plate such that they extend over the edge portions of the cavitation plate. The forces generated upon the mounting plate will accordingly be distributed to the anti-cavitation plate as well as the adaptor. The hydrofoils employed in the assembly preferably include rudders, which obviate the need for the counter-rotation tab replaced by the adaptor.