Abstract: A sailboat, adaptable to use in water, on land and on ice or snow, having a longitudinal beam support extending outwardly in front of the bow and engageable with the bow of the hull structure. The hull structure also having a mounted airfoil support member extending transversely across the aft portion of the sailboat. The longitudinal beam support and the airfoil support member being adaptable to a skate element mounted on the outer reaches of the support members and/or to the mounting thereon of wheel elements that provides the vessel with a means of locomotion. The support members being braced or tensioned at the outer reaches thereof by guy wires extending therebetween to orient and align the support members and brace same in relation to the hull structure of the sailboat. The hull structure also has a keel housing member integral therewith, a centerboard keel member being slidably disposed within the keel housing member.