Abstract: A wing type airfoil is used to propel a vessel. The airfoil comprises a mast, a counterbalancing airfoil and a driving airfoil. The mast is elongate and has upper and lower portions, the lower portion is adapted to be connected to the vessel and extends upwardly therefrom. The counterbalancing airfoil has a first angle of attack orientation and is connected to the mast. The driving airfoil has a second angle of attack orientation and is connected to the mast below the counterbalancing airfoil. The counterbalancing airfoil and the driving airfoil have different angles of attack which are independently adjustable with respect to the vessel.