Abstract: A portable marine shelter that includes a frame assembly having two lower spaced apart longitudinally extending members, or float bars, and a flexible cover that fits over the frame assembly to provide an enclosure to store a boat and the like. A floatation system includes numerous sphere-shaped floats that are rotatably attached to the lower frame members, the floats are also free to move longitudinally along predetermined sections of the lower frame members. The floats are substantially equally distributed between the two lower members and along each individual member. The loosely attached floats enables the shelter to accommodate wave and wind generated motion without unduly stressing the frame assembly of the boat sheltered therein. The entire shelter is loosely attached to a dock and loosely anchored to the bottom of the lake, etc. to provide a structure that securely protects a boat yet is capable of being moved easily to different locations.