Never mind boxers or briefs—it's a Speedo that's, well, making waves.

Roy Lester, a 61-year-old former lifeguard at New York's Jones Beach, was relieved of his duties for refusing to wear a Speedo for his annual swim test. Lester, a triathlete with more than 40 years of experience, is suing the state for age discrimination.

New York State policy requires male lifeguard candidates each year to complete a 100-yard swim in one minute and 15 seconds wearing either "boxer, briefs, or board shorts." Lester says the state is trying to shake old lifeguards by nixing his original swimsuit choice: tight-fitting shorts that reach nearly to the knee. (Women are required to wear a "standard one piece or two piece bathing suit.")

"I wore a Speedo when I was in my 20s," Lester told the New York Daily News. "But come on. There should be a law prohibiting anyone over the age of 50 from wearing a Speedo."  

"Basically, the state's been trying to get rid of the older guys. They really don't like older lifeguards," Lester told ABC News, saying he was fired from his job working at Jones Beach on New York's Long Island in 2007. He had worked there each summer for decades and showed up to take the annual swim test in his normal swimwear. When he refused to change into a Speedo, he was fired, according to the suit. He returned in 2008 and faced the same problem.

Lester, a bankruptcy lawyer by profession, filed two lawsuits. Both were dismissed on technical grounds in 2008 and 2009, but now an appellate court has reinstated Lester's claim. His case could go to trial later this year or next year in New York's Nassau County.

"Older people…prefer a more modest swimsuit and thank goodness they do," Lester told ABC. "There's a thing called aging and there's a thing called aging gracefully."

A former lifeguard union head estimates that more than 80 percent of lifeguards at Jones Beach (one of eight state beaches in New York) are older than 40.

"This was not right," said Lester, who is representing himself in the age discrimination claim and who has previously accused state officials of disciplining Jewish lifeguards more often than nonJews. "To me, the whole key to being a good lifeguard is experience. An older guy sees a save before anyone else. [He knows] the water."

State officials would not comment.

The issue for Lester isn't about getting his job back; he's since found a job lifeguarding at a private beach. It's about taking a stand.

He told the Daily News: "I could have passed that test in dungarees."