An underwater fun toy includes a buoyant body having an upper and lower surface and a receiving portion communicating through the upper and lower surface, an underwater member receivable in the receiving portion having a first and second surface, first and second engaging portions formed on the receiving portion and the underwater member, and a plurality of stand portions for supporting the buoyant body which engages with the underwater member at a desired height from the bottom of water. The first and second engaging portions are engageable with each other and disengageable from each other, wherein in use the buoyant body engages the underwater member and is sank in water such that stand portions keeps the buoyant body at a desired height above the bottom of water, and when the underwater member is depressed to disengage from the buoyant body thereby said buoyant body floats to the surface of the water and the underwater member remains sank.