A cover system for a boat includes a bimini frame securable to the boat and displaceable among an open position, a storage position, and a cover position. A flexible top is coupled with the bimini frame, and a cover is positionable over the bimini frame with the bimini frame in the cover position. The bimini frame thus functions as a support structure for a mooring or trailering cover. With the described bimini frame, one cover size can fit multiple seating and deck configurations without the need for a separate cover design for the various configurations.