It is illegal to swim in central park. Many outdoor swimming pools in the Icelandic capital of Reykjavik are heated so effectively by this method that it remains open and in use all year round. The turbopump on the Space Shuttle main engine is so powerful it could drain an average family-sized swimming pool in 25 seconds. Esther Williams did not win any Olympic medals for swimming or for diving. Right now as you sit reading this, more than 100,000,000 microcreatures are swimming, feeding, reproducing, and depositing waste inside that area behind your lips.
Kangaroos are excellent swimmers.
Bill Gates decided to hold a contest for the lawyers. Whoever wins gets to handle all of Microsoft's business. The day of the event, the Gates' estate is swamped with lawyers, all eager for the nod from the richest man in the world. He leads them to an enormous swimming pool filled with piranha. Then he snaps his fingers.