April marks the beginning of the season for swimming with whale sharks down under. The other good news is they're not sharks, so you don't have to worry about being eaten. They're just really, really big 15 ton fish. In fact they're the biggest fish in the sea. But we can keep that to ourselves so you can tell people you swam with 15 ton whale sharks. It should impress at cocktail hour. Ningaloo Blue Dive is probably your best bet if you want to be guided.