1287487 Air cushion vehicles SOC D'ETUDES ET DE DEVELOPPEMENT DES AEROGLISSEURS MARINS TERRESTRES ET AMPHIBIES 29 Dec 1969 [30 Dec 1968] 63043/69 Heading B7K A skirt element of a skirt assembly for a ground-effect machine comprises an outer wall portion 2 and an inner wall portion 4 secured to a frame 1 of U-shape, the wall portions bounding a substantially crescent-shaped space 6 between them. The frames 1 are mounted on the platform (7) of the ground-effect machine adjacent each other to form a compartmented-skirt assembly and a common inner compartment 5. The inner wall portion 4 is cut at the top edge 4b to permit flow of fluid, which is delivered to compartment 5 from a fan, to compartments 6. In a modification, Fig. 10, to raise the skirt elements over obstacles, each element disposed at the rear of the vehicle is provided with a grating 10 secured by wires 11 directly to the platform (7) of the body structure of the vehicle.