Hydrofoil craft that receives a portion of its lift from a single buoyant pod located below a traditional upper hull. The foils are attached to the pod or “lower hull” which is connected to the upper hull by one or more low-waterplane area struts. Like a traditional hydrofoil, the HYSWAS operates on its upper hull at low speeds where the large waterplane area provides the vessel with the necessary hydrostatic stability. As speed increases, the foils generate sufficient lift to raise the upper hull out of water and stabilise it in the presence of roll and pitch moments exerted by the sea and wind.