A watercraft with a rigid outer hull having a substantially circular shape in plan view and a rounded bottom surface for contacting a body of liquid, and a rigid top surface disposed opposite said bottom surface and integrally formed with the outer hull, the top surface having an annular stability portion with convex walls in cross -section and a recessed flat-bottomed deck portion adapted to receive a person, and an edge of the recessed deck portion being disposed inwardly from an outermost edge of the top portion by a distance, and a method for using same.