Abstract: Multiple-hull catamaran vessels equipped with hydrofoils have two hulls connected by a deck. Transverse to the hulls below the waterline are three or more hydrofoils, the trim bow and stern hydrofoils, and the relieving middle hydrofoil or a group of hydrofoils. The bow and stern hydrofoils are mounted at a distance not less than 30% and 20% of the hull length to the bow and stern, respectively, from the center of mass. Lift arising on all hydrofoils when sailing at a maximum calculated speed in calm sea reaches 60-70% and in calculated rough seas 20-40% of the catamaran's full weight. The bow foil, middle and stern foils account for 0.05-0.15; 0.15-0.30; 0.10-0.25 shares of the catamaran's full weight, respectively. When sailing in rough sea and during vertical travels of the hulls (vertical rocking), "submergence--emergence" takes place which leads to "increase--decrease" of the lift thereby reducing vertical travel amplitude.