Abstract: Low drag underwater submerged displacement hulls which can be used as independent vessels or as underwater displacement hull portions of a vessel whose main hull is at sea level are disclosed which have improved lift to drag ratios. The disclosed vessels have outer surfaces whose shapes are defined in plan and elevation by generally parabolic curves.

Abstract: A high speed ship is disclosed which includes a hull structure having a bow portion and a stern portion with the hull being normally supported above the surface of the water when in operation. A forward strut depend from the bow portion of the hull structure and is subtended by a first transverse displacement foil. A set of midship dual struts depend from the hull structure aft of the forward strut; the aft dual struts are subtended by a second transverse displacement foil extending laterally between and connected to each of said struts. The second transverse displacement foil has a beam equal to or greater than its length and provides 70% or more of the major buoyancy for the ship during operation to maintain the hull above the surface of the water during operation. The forward foil provides less than 30% of the buoyancy of the vessel and has a beam less than the spacing between the aft struts.

Abstract: A high speed ship is disclosed which includes a hull structure having a bow portion and a stern portion with the hull being normally supported above the surface of the water when in operation. A forward strut depends from the bow portion of the hull structure and is subtended by a first transverse displacement foil. A pair of midship struts depend from the hull structure aft of the forward strut; the aft struts are subtended by a second transverse displacement foil extending laterally between and connected to each of said struts. The second transverse displacement foil has a beam equal to or greater than its length and provides 70% or more of the major buoyancy for the ship during operation to maintain the hull above the surface of the water during operation. The forward foil provides less than 30% of the buoyancy of the vessel and has a beam less than the spacing between the aft struts.

Abstract: A small water plane area vessel is disclosed which includes at least one normally submerged hull, a superstructure normally located above the level of the water during operation of the vessel and at least one strut connected between the superstructure and the submerged hull. The vessel has a design draft water line located between the normally submerged hull and the superstructure and at lease one buoyancy pod on the strut located above the design draft water line and below the superstructure. The strut has a water plane area at the water plane of the pod which is larger than the water plane areas thereof above and below the pod.

Abstract: A small waterplane area twin hull (SWATH) vessel is disclosed which includes a pair of normally submerged hulls that provide buoyancy support for the vessel. An upper hull platform located above the design water line of the vessel is connected to the submerged hulls by at least two pairs of struts respectively associated with each of the submerged hulls. The submerged hulls are arranged to define an acute angle between them. In one embodiment the vertex of the angle is rearward of the submerged hull and in another embodiment it is forward of the submerged hull. In other embodiments of the invention the struts are arranged to define dihedral angles between the struts and the upper hull platform. In addition, the struts may be angled with respect to the center line of the vessel.

Abstract: A marine vessel is provided which comprises a platform member, two parallel hulls disposed below the platform and adapted to be below the water surface when the ship is in operation, each of the hulls consists of an after section, a forward section having a smaller cross-sectional area than the after section and a central section having a cross-sectional area substantially smaller than that of the forward section and supported only by the junctions with the forward and after sections. Both forward sections and both after sections are joined to the platform member by strut-like members which are tapered so that their waterplane areas increase rapidly between the waterline and their junctions with the platform member.