Patent ID: 8662000

Claim:
A buoyant structure ( 10 ) comprising: a hull ( 12 ) characterized by an upper frustoconical portion ( 12 c ) having inward-sloping walls disposed above a lower frustoconical portion ( 12 d ) having outward-sloping walls with a circular keel; and a tunnel ( 30 ) with a tunnel floor ( 35 ) formed within said hull at a waterline elevation, said tunnel ( 30 ) said tunnel comprising a first opening in said hull opening to an exterior of said hull and dimensioned so as to receive a watercraft ( 200 ) therein, a boatlift assembly ( 40 ) disposed within said tunnel ( 30 ) for lifting the watercraft ( 200 ) over the waterline while contained in the tunnel, and a main deck ( 12 a ) secured to said hull that completely covers said tunnel ( 30 ).