The performance potential of semisubmerged ships

As a contribution to the current debates about the potential of semisubmerged ships (cu S), this paper presents estimates of the lowest possible resistance/displacement ratio. That is, the resitance of the submerged form alone is calculated, without reference to the additional components due to necessary struts, rudders, and other appendages. It is suggested that the Priest hull configuration is better than the more recent SWATH, because of its reduced wetted area, and that, like hydrofoil and SES, cu S should probably rise up is the water for high-speed flight. This then removes the serious constraint that the struts must provide adequate hydrostatic stability, since this stability can now be provided by the upper hull, which is in contact with the water at low speeds. At higher speeds, roll stability can be provided by the submerged foils which in any case seem to be required for adequate control.