HULL UNIT WITH A HYDROFOIL SYSTEM AND MARINE VESSEL

An auxiliary hull unit detachably mounted to a transom on a marine vessel, wherein the hull unit is mounted at least partially below the water line of the vessel and arranged to extend rearwards parallel to the rearward extension of hull sections adjacent to the hull unit. The hull unit comprises a rear hydrofoil system for the marine vessel; the rear hydrofoil system comprising at least one pair of foldable hydrofoils which are pivotable in a lateral direction relative to the hull unit, wherein each hydrofoil is controllable by at least one actuator for displacement of the at least one pair of foldable hydrofoils in the lateral direction of the hull unit between a stowed position and a deployed position. The hull unit can be provided with a propulsion unit.