Abstract: A wind-propelled hydrofoil comprising a forward assembly with at least partially submerged forward foils and a fully submerged aft foil. The forward foils (43, 44) are such that the resultant of the vertical forces drops when said assembly is translated vertically upwards, with a heave characteristic (F), and increases when said forward assembly is subject to upward pitching, with an incidence characteristic (A). The aft foil (46) has an incidence characteristic (R) such that R(d-g)-Ag+F(g.sup.2 +r.sup.2)>0, wherein d is the distance between the aft foil (46) and the center of heave, g is the distance between the center of gravity and the center of heave, and r is the gyration radius of the hydrofoil.