In the world of aquatics,Michael Phelps needs no introduction. Now considered one of the greatest swimmers of all time, millions watched him in the 2004 Olympics, and even more cheered him on from their living rooms in 2008.

Following his two older sisters into the water, Phelps got his start in aquatics at the now- legendary North Baltimore Aquatic Club, reportedly as an outlet for his ADHD. To date, he’s won 16 Olympic medals and broken approximately three times as many world records. But as much as aquatics has done for Phelps, it’s likely he’s done more for aquatics.

His history-making eight Olympic gold medals have opened the pool doors to millions, inspiring a generation of children and adults to dive in. According to USA Swimming, in 2009 the organization recorded its largest-ever single year membership gain.

He’s also helped increase media coverage of swimming. Phelps himself has published a book and made millions as a pitchman. He’s been seen in advertisements for a number of products. In addition, following the 2008 Olympics, Sports Illustrated Group commissioned the first-ever poster of a Sports Illustrated magazine cove, showing Michael Phelps wearing his eight medals — in homage to the cover that showed Olympic swimmer Mark Spitz with his seven golds.

Moreover, NBC-TV, which aired the 2009 World Swimming Championships, has secured rights to the 2012 Olympic trials and the 2012 summer games in London. It will also broadcast the 2010 and 2011 National Championships.

Media coverage is undoubtedly good for aquatics; however, since the Beijing Games, Phelps has almost as many headlines for his exploits outside of the pool. In February 2009, a photo of Phelps smoking marijuana surfaced, tarnishing his “Golden Boy” image.

Of course, Phelps is not yet 25 years old, so his ultimate legacy is not yet written. He is still competing, with eyes toward swimming in the 2012 London Olympics.