Abstract: A water-impervious material forms a protective envelope around the hull of a vessel. Interconnected pipe sections in a tubular opening around the upper edge of the envelope form a rigid frame to maintain the shape of the envelope. A pair of split rods pivotally connected at two points between pipe sections create a front collapsible portion of the envelope. The weight of the pipe sections in the front collapsible portion cause it to sink and pivot downwardly to allow a vessel to enter and exit the envelope. Ropes and blocks between the front portion and the floating piers are used to raise the front collapsible portion and the ropes tied to the vessel to maintain the front portion in place. The remainder of the envelope is fitted with a series of floats so that the envelope encircles the vessel to prevent marine growth on the hull of the vessel. Counterweights on ropes through pier blocks and connected to the envelope around its perimeter maintain it in place around the vessel.

Abstract: An anti-fouling protector in the form of flexible envelope complementary to the underwater body of a vessel's hull is negatively buoyant and, when not in use, is stored on the bottom of a mooring slip. The invention includes structural features of the slip for guiding endless ropes fixed to the envelope for raising it around the vessel's underwater body when the vessel is moored in the slip, just before a vessel leaves the slip, lanyards connected to the envelope are detached from the vessel and the envelope sinks to its storage position on the bottom of the slip, where anchored lower rope guides prevent the envelope from being moved away by current.