In 1911, Hawaiian swimmer Duke Kahanamoku swam 220 yards- 201 meters- in 2:42.4. That doesn't sound impressive now-- in Beijing in 2008, the last-place-finishing swimmer, Emanuele Nicolini of San Marino, swam the 200-meter freestyle in 1:59.47. And he came in dead last. Michael Phelps swam it in 1:42.96.
But this was 1911. And Duke was swimming in a Honolulu harbor, without getting to make any turns. The time sounded so incredible that when it and Duke's other times that meet were submitted to the Amateur Athletic Union, they figured there must have been some mistake. In fact, they refused to recognize his times, and then tried to claim he was aided by some sort of current in the harbor.
Duke did get some other times recognized, though: the times that won him a gold and a silver in Stockholm in 1912, two golds in Antwerp in 1920, and a silver in Paris in 1924. His Antwerp gold set a then-world record in the 100-meter freestyle, a time of 1:00.4, and he ran the anchor leg in the 4x200 freestyle relay to help set another then-world record of 10:04.4.
But Duke's true strength wasn't in the water-- it was on it. He is known as the Father of Modern Surfing, popularizing the sport and in fact introducing it to Australia. And one year after his Olympic days were over, he performed perhaps his greatest surfing exhibition.
In 1925, a ship capsized off the coast of Corona del Mar, California, killing 17 people. 12, however, were saved. Eight of them were saved because Duke had paddled out on his board to grab as many people as he could. The other four were saved by a friend of Duke's, Gerard Vultee, also on a surfboard.
A few years later, Vultee would work with a man named Tom Blake to develop the first hollow surfboards. Blake worked as a lifeguard.
And now you know why lifeguards carry surfboards.