Abstract: An inflatable kayak constructed of drop-stitch material. When inflated, the drop-stitch members form a rigid, planar structure. To form a non-planar contour in one of the surfaces of a drop-stitch member, the opposing surface is folded over onto itself and a strip of glue along the fold adheres the opposing surface along the glue strip, thereby forming a V-fold extending into the interior of the drop-stitch member. When the member is inflated, the V-fold will alter the profile of the opposing surface and cause the first surface to project away along that profile. The V-fold can be augmented by use of a V-tape or contour member within the V-fold. Using a contour member in the V-fold creates profiles that a fold alone cannot produce.

Abstract: The present invention relates to an inflatable stand up paddle (SUP) board that has a separate air chamber formed therein in addition to a tube that forms a main body, thereby achieving more enhanced safety, and conforms to national safety regulations. The SUP board comprises: a main body that is formed in the shape of a long plate and has a plurality of shape maintaining lines, each having opposite ends coupled to upper and lower internal surfaces, and a first air injection port installed on the front side of the upper surface thereof; a side sheet air-tightly bonded to the main body along the outer periphery thereof to form an air tube along with the main body; and an inner tube that is provided on the outer periphery of the main body and has a second air injection port installed on the outer surface of the side sheet to allow air to be injected thereunto, wherein the outer surface of the inner tube is attached to the internal surface of the side sheet.