John Vargas has spent more than 40 years in water polo as a player and coach. He has found success at every level, including high school, college and the U.S. National Team. The youngest of three water polo–playing brothers raised in Hacienda Heights, California, Vargas was a standout at Los Altos High School before heading to UC Irvine, one of the preeminent programs of the time. Vargas helped the Anteaters to a National Championship in 1982 and twice earned All-American honors. He didn't go far from the Irvine campus after his college days, becoming the head coach at Corona del Mar High School. He continued to play for the Newport Water Polo Foundation, winning three U.S. Open titles and working toward his Olympic dream.

While his older brother Joe made Olympic rosters in 1980 and 1984, Vargas found himself as the final cut for the 1988 roster. Never the biggest player in the pool, Vargas remained determined and helped Team USA to a FINA World Cup crown in 1991. He broke through on the Olympic stage at the 1992 Games in Barcelona with a fourth-place result.

From there Vargas focused on coaching, joining the Team USA staff ahead of the 1996 Olympic Games, while still coaching at Corona del Mar. He earned the top job with Team USA, winning World Cup gold in 1997 en route to a sixth-place finish at the 2000 Olympic Games in Sydney.

After a stellar run with Corona del Mar that saw seven CIF titles and five runner-up finishes, it was off to the college ranks. Vargas took the reins of the Stanford University men's program, winning an NCAA Championship in his first season in 2002. In a 20-year run on The Farm, he coached a host of Olympians and All-Americans, while winning five MPSF titles and adding a second NCAA title to his résumé in 2019. He added to that five second-place finishes and reached the semifinals on three other occasions. He was also a mainstay on the club scene, guiding the Stanford Water Polo Foundation to two US Open titles on the men's side. Vargas retired from Stanford following the 2021 season, ending with 389 career victories.