You can skip rocks and stones along the surface of water if thrown at the correct angle or speed but they would sink to the bottom once they lost their momentum. Cruise ship would float for sure obviously otherwise everyone onboard would drown/die. Beach ball as well because it has very light weight/round qualities and would float good on the surface. The other choices would be more likely to sink to the bottom I would think because of gravity and or weight anyways. Just spit balling here though.