A buoyancy tank for a portable floatation apparatus which allows for the elevation of a watercraft above a water-line and which allows for the removal of the watercraft from a body of water. The buoyancy tank has at least one and/or a plurality of integrated cylindrical structures which supports the floatation apparatus in transport and storage. The integrated cylindrical structures provide sufficient support to allow the removal of the floatation apparatus by use of a boat lift and further provide sufficient support to allow a watercraft to be stacked on top of the floating apparatus while the floating apparatus is stacked on top of the floating apparatus for the purposes of storage. A plurality of said buoyancy tanks may be connected to the portable floatation apparatus by use of connecting means. The portable floatation apparatus should have a pumping device which pumps a sufficient volume of air into a plurality of the buoyancy tank which is effective to selectively and conveniently elevate a watercraft above a water line.