How do you quickly raise a sunken ship full of sheep? The Danish inventor Karl Krøyer came up with a very creative solution: pump buoyant bodies into the ship to achieve sufficient upward lift to bring the ship back to the surface. The solution was so creative he got a patent on it. In a 1949 Donald Duck story, titled The Sunken Yacht a ship is raised by stuffing it full of ping-pong balls. That kind of prior art could kill the patent. But whether the story was actually used by a patent office to refuse the patent (application) remains unclear. --Arnoud Engelfriet,Ius Mentis, The "Donald Duck as prior art" case, 2007
Ping-pong balls can be used to raise a sunken ship.
Even though it took an impractically large number of ping-pong balls (27,000), when enough of them were piped into the Mythtanic II, the boat rose to the surface. --MythBusters,, Episode 21: Ping-Pong Rescue, Air Date: November 3, 2004