A spa cover constructed of layers of pliable insulation encapsulated within a weatherproof vinyl reinforced fabric or a rubber membrane which is attached to rigid square support tubes that run parallel to the short end of the spa. The encapsulated insulation is fastened to the bottom of the square support tubes with corrosion-free nylon anchors which allows the soft insulation assembly to span over the water and rest directly on the spa bartop surface sealing the heat in and keeping debris out. An arched fiberglass rod structure supports a weatherproof rainfly which is permanently affixed to the flat cover assembly to shed rain and debris. The entire assembly is held in place at each end with adjustable straps which stretch the cover from end to end keeping the rainfly taut. Removing the cover to access the spa involves undoing the straps on one end and rolling the cover assembly towards the other end until the desired amount of spa exposure is reached. Covering the spa after use is just the opposite procedure.