Disclosed is a surface vessel with motorised mechanical propulsion including a fusiform hull and a keel in the bottom part of the hull, the hull having an elongate shape in a longitudinal direction of the vessel, the keel including, at the bottom end of same, a bulb linked to the hull by a linking part of the keel, the maximum width of the linking part being smaller than the maximum width of the bulb, the maximum length of the linking part being smaller than the maximum length of the bulb, the lengths and widths being considered respectively in the longitudinal direction of the vessel and a horizontal transverse direction perpendicular to the longitudinal direction. The hull has a total width to total length ratio of less than 0.2 and a maximum length of less than 20 metres.