Successful continuous operations in heavy seas and surf were achieved. Landings and departures were performed through surf with breaking waves as high as 7 to 8 feet, and a capability for higher breakers is indicated. Vehicle stability and ride characteristics are considered superior to those of hydrofoils and planing hull craft no seasickness or discomfort was reported by passengers or crew. The maximum normal bow accelerations, recorded in the aforementioned 8- to 12-foot waves, were 1.5g. In sea state 3, approximately 80 percent of all normal bow accelerations fell below 0.6g. Amidships, all accelerations were significantly lower. The moderate acceleration levels can be attributed to the damping effect of the air cushion. Although the flexible skirt design was adequate for this program, it cannot be considered sufficiently developed for operational usage. Maintenance and repair hours were far in excess of acceptable values. A high degree of mission reliability with major skirt damage, however, was demonstrated on more than one occasion. Small arms fire damage, therefore, may be considered insignificant.