Abstract: One embodiment of the invention provides a multihull watercraft having outermost hulls, a length, and a pair of propulsion units positioned inboard of its outermost hulls in a central ½ of the watercraft length. The propulsion units include propellers which are positioned to engage the water within the central ½ of the watercraft length and draft less than the outermost hulls. Because the outermost hulls provide protection from obstacles, the propulsion units can be operated propeller-end first, at a sufficiently high efficiency so that solar power for electric motors becomes an economically viable power source.

Abstract: Inflatable hull configuration and connection for a multihull vessel. The inflatable hulls have a longitudinal structural member fastened to the top of the inflatable hulls, with a central body of the multihull vessel supported on the longitudinal structural members by forward and stern legs. The forward legs support the forward part of the central body through a ball joint that allows the forward legs to rotate as a unit relative to the central body, and have their lower ends attached to the forward part of the longitudinal members, each through a spring supported ball joint. The stern legs are each rigidly coupled to the central body, with their lower ends connected to the aft part of the longitudinal members to allow rotation about a vertical axis and a transverse axis, but not the longitudinal axis. A detailed embodiment is disclosed.

Abstract: An amphibious vehicle for land and water use comprises a main mono hull section and a pair of port and starboard sponsons which are movable from a stowed position under a main vehicle deck adjacent to the mono hull and a fully deployed position in which the sponsons are spaced apart from the mono hull by at least one hull width. The sponsons are each pivotally connected to the main hull by means of a pair of respective arms which together with the sponson and the hull define a parallel type four bar linkage. The sponsons stabilise the vehicle on water and are readily stowed to allow vehicle mobility on land.