Abstract: A self-supporting marker buoy includes an upper unit, a lower unit, and a rim-engaging cover. The upper unit is a frustum which further includes a base opening facing downwards, a hollow center, and a base rim around the base opening. The lower unit is an upside-down frustum, which further includes a top opening facing upwards, a hollow center, a top rim around the top opening, and a water entry at the bottom of the lower unit. The radius of the base opening of the upper unit is less than that of the top opening of the lower unit.

Abstract: An improved entertaining balancing ball set includes a basis ball of a pre-determined outer diameter and a rolling ball of a smaller diameter. The basis ball includes one or more grooved orbits of which the shape could be branching, labyrinth-like, curving, extending, etc. The grooved orbits include a skewed side, one or more traps, a starting point on one end for each of grooved orbits, and a destination on the other end for each of grooved orbits. The rolling ball has a diameter that is determined based on the width of the groove orbits over which the rolling ball is to move within. The inside of the basis ball could be either hollow or solid.

Abstract: A frisbee structure, having a piercing hole on the central part, comprises a spinning structure, which further comprises an upper coupling member, a lower coupling member, a fastener and a revolving component. The upper coupling member is arranged on one end of a fastener, the other end of the fastener is hooked up with the revolving component and the lower hook portion on one end of the revolving component is hooked up with the lower coupling member. The assembly of the spinning structure and the frisbee is to enable the upper coupling member to be separated from one end of the fastener, enable that end of the fastener to be corresponding to the piercing hole on the frisbee, and then enable the upper coupling member to be buckled and positioned on the other side of the piercing hole of the Frisbee and formed in one piece with the frisbee.