25. A convertible seating system for a marine vessel having a bow and a stern, the convertible seating system comprising a sofa having a sofa backrest and a sofa seat that extends transversely relative to the sofa backrest, wherein the sofa seat provides a sofa seating surface for a seated occupant facing the bow and wherein the sofa backrest provides a backrest surface for the seated occupant facing the bow, and further wherein the sofa seat comprises a sofa base and a sofa bed that is extendible out from under the sofa base into a lounge position in which the sofa seat and the sofa bed together provide a contiguous sunpad for an occupant of the marine vessel laying in a prone position, wherein the sofa comprises a sofa frame that supports the sofa seat and the sofa backrest, and wherein the sofa frame is pivotable relative to a hull of the marine vessel, which defines a storage area below the sofa seat.