Roll and heave stabilized buoyant body

A buoyant body provided in the shape of a major spherical zone of one base and in which said weight is distributed so as to make said body tend to float with said base up and with the center of gravity displaced along an axis perpendicular to the base from the spherical center toward the intended bottom of the body so as to provide a righting moment making the body tend to float with a diametric plane parallel to said one base and generally parallel to the water line, and with the water line intersecting the spherical surface in a plane parallel thereto so that a predetermined portion lies above the water line and a horizontal plane of said sphere passing through the center of gravity lies beneath the water level, said body being also formed to include a generally frusto-conical structure tangent to said zone at said base and a generally cylindrical surface extending upward from said frusto-conical portion, said body, said frusto-conical structure and said cylindrical surface being formed so that the center of gravity, the righting moment and the stability of heave and roll remain undisturbed, said spherical body and the contents contained therein being inherently arranged so that said body is stable against both roll and heave by providing the natural period of its oscillation about any horizontal diameter within the intersecting plane and the natural period of vertical oscillation along a diametric axis perpendicular to the horizontal plane are simultaneously both greater than the period of any waves of significant height reasonably expected to be encountered by the body thereby maintaining said base in generally stable horizontal position.