FORTUNE — Americans love to swim: 93 million people do so and spend $1.4 billion on suits every year. For professional swimmers, this means both lucrative sponsorship and a deep-pocketed support organization — USA Swimming raises about $100 million a year, from its nearly 300,000 members’ registration fees, taking a share of about a sixth of that money for its own revenue. Much like running, swimming is a sport in which the elites are supported by the hobbyists. The cut from member registration — about $16 million in 2011 — keeps the elites afloat.
National team members ranked 16th in the world or higher in their respective events who sign on as partners and commit to a group of events and appearances can receive a $3,000-a-month stipend, but even elite swimmers who opt out receive strong support roughly equivalent to a starting teacher’s salary. USA Swimming spent over $7 million on its National Team swimmers last year, and even provides stipends to college athletes eligible under NCAA rules. And everyone gets a free Speedo.
Ryan Lochte is a special case: While Lochte has received such stipends in the past, he can now afford to take a lower rate of support from USA Swimming (though he still pockets an estimated $30,000 a year in funding and reimbursements). That’s because as a gold-medal favorite — in the 200-meter backstroke and individual medley, where he’s beaten Michael Phelps — Lochte is set to earn about $2.3 million this year. Much of that comes from Lochte’s strong sponsorship lineup: Lochte has longstanding relationship with Speedo and Gatorade, and also counts Nissan, Mutual of Omaha, Gillette, Ralph Lauren and AT&T (T) as sponsors, the latter three in anticipation of the London Olympics.
While the majority of those deals earn Lochte upward of $250,000, they also keep him well supplied and outfitted. From Speedo and Ralph Lauren, Lochte gets all the swim gear and clothes he needs; Gillette provides him its family of products, and AT&T offers equipment such as a smartphone; Nissan provides Lochte with a car. Some of those products also make it to Lochte’s parents, typically at Lochte’s own request. Lochte also benefits from direct work with Gatorade scientists who monitor his training and determine a plan for best integrating the company’s line of products into his training and recovery — critical for an athlete who, according to his manager Erika Wright, is in water too much to like drinking it.
In exchange for those levels of support, Lochte appears in commercials and makes appearances for his sponsors, from swim clinics to the Super Bowl. Lochte must also perform well in London to unlock even bigger dollars. While his sponsorships account for just under $2 million of his base salary, a clutch of gold medals can unlock a bonus from Gatorade and an even bigger one from his largest sponsor, Speedo, which would push him over $1 million for that deal alone. (Lochte, for his part, says that he’s not going into London “looking at a number” of medals to target.)
The money can add up fast during an Olympic year. Wright says that if her client has a strong showing, new sponsors will line up to pave his way to Brazil in 2016. But whether Lochte’s the big man in the pool after London or has a tough competition, he will be financially secure from interests outside of swimming. Lochte sees himself designing in mainstream fashion, and he’s already gotten his feet wet working with Speedo on flip flops in 2010 and now in 2012 with his own clothing line, “Rocker.” Speedo will also debut lines with two other high profile swimmers, Michael Phelps and Natalie Coughlin, but the company says only Lochte had a close hand in the design. Lochte’s also built some fashion cred with a recent appearance (rare for men) on the cover of Vogue, modeling work he says he would happily continue.
Lochte also plans to franchise his own swimming clinics someday, but in the meantime, he’s looking at an additional source of revenue through workout videos developed with his trainer, “Lochte HardCore.” That will come through a company his team has just filed to incorporate, Lochte 180, to better manage his diversifying business interests and ease the tax burden on his sponsorship income.
Add it all up, and Lochte could earn as much as $3 million if the schedule and the races break in his favor — good for a man with an eye for Lamborghinis. Now that teammate and rival Michael Phelps has declared London his last Olympics, even bigger future paydays might make him the car dealership’s new best friend.
For more on the London Summer Games, click on the links below
The (big) bucks behind the 2012 Olympics
Wall Street gets behind the games
Henry Kissinger: Scholar, statesman, Olympic fan
Will NBC’s investment pay off?
Rich Sport: U.S. Olympic swimmers float on cash
Poor Sport: When Olympic athletes have to moonlight
London locks down for the Olympics
BMW’s ultimate Olympic machine
13 steps to keeping the London Olympics safe
London’s extreme Olympic makeover
A shorter version of this story originally appeared in the June 11, 2012 issue of Fortune.