The invention relates to a vessel (1) comprising a hull (2) for non-planing operation, during operation displaying a waterline (3) and having a forward direction in a horizontal plane (4) with a forward portion, an aft portion (5), and a central portion, the aft portion having a smaller water displacement relative to a water displacement of the central portion; and an aft, primary foil (6) affixed to the aft hull portion with a connecting member (7), configured to be below the waterline during operation, spaced from the hull, the aft foil having a span, a chord, a profile, a leading edge (8) and a trailing edge (9) relative to the forward direction, characterized by adjustment means (10) connected to the aft foil and configured for adjusting an angle of incidence (βc, af) of the chord of the aft foil.