One of his Donald Duck comic books - "The Sunken Yacht" (1949) - was the inspiration for a maritime salvage operation fifteen years later. In the comic, Donald and his nephews re-float Uncle Scrooge's sunken yacht by pumping it full of ping-pong balls. In 1964, the freighter "Al Kuwait" sank with approximately 6000 sheep in its cargo hold in a fresh water harbor near Kuwait City. Since the harbor was the source of most of the city's drinking water, it was feared that the rotting sheep would poison the city's water supply. A Dutch engineer named Karl Krøyer remembered the comic and suggested pumping 27 billion polystyrene balls into the ship's double hull to re-float it. The plan worked and the city's drinking water was saved. Later, when Krøyer applied for a Dutch patent for this process, he was denied because it was deemed that the idea belonged to Barks.