With barely a year to go until the Rio de Janeiro Olympics, most of the world's top swimmers and divers will compete at the FINA world championships in Kazan, Russia.
The July 24-Aug. 9 event is the biggest international meet of the year, with athletes measuring themselves against the best to see the standards that will be required to earn them a berth in next year's Olympics.
Diving, synchronized swimming, water polo and open water swimming dominate the first week of the championships, with swimming and high diving set for the second week.
Here are some athletes and events to watch at worlds:
KATIE LEDECKY -- The 16-year-old American swimmer won four gold medals and set two world records at the 2013 meet in Barcelona. She plans to be busy this time around, too, equaling teammate Missy Franklin with four individual events. Ledecky is entered in the 200, 400, 800 and 1,500-meter freestyles. She holds the world records in the three longest distances. Ledecky and Franklin will be part of a deep field in the 200, where Franklin is the defending champion.
SUN YANG -- The 23-year-old Chinese swimmer is the defending champion in the 400, 800 and 1,500 freestyles. He also plans to swim the 200 free at worlds. He owns the world record in the longest distance and ranks among the top 10 times in the other three events. Sun will be on his biggest stage since serving a suspension last year for a positive doping test.
BILL MAY -- The American will be part of the synchronized swimming mixed duet competition, being held for the first time at worlds. May has returned to the sport in his 30s after winning 14 U.S. national titles in the late '90s. May was once banned from international events because of his gender. He currently swims in Cirque du Soleil's "O'' show in Las Vegas.
KATINKA HOSSZU -- The Hungarian known as swimming's "Iron Lady" is keeping quiet about her event schedule going into worlds. She's ranked among the world's top 10 in the 200 and 400 freestyle, 100 and 200 backstroke and 200 and 400 individual medley. While Hosszu is known for a herculean schedule at meets, it seems unlikely the U.S.-based swimmer would attempt all six individual events and participate in the relays in Kazan.
MISSY FRANKLIN -- Newly turned professional after competing two years in college, Franklin faces a big challenge in following up her performance at the 2013 worlds. She won a record six gold medals in Barcelona while swimming in seven events, including all three relays. Franklin hasn't raced long course meters as much this season because the first half of the year she was competing for the University of California. She broke her own American record while winning the 200-yard freestyle at the NCAA championships last spring. She has returned to her home in high-altitude Colorado and resumed training with her longtime coach Todd Schmitz.
CHINESE DIVERS -- They figure to dominate just as they did in 2013, when China won nine of 10 events. China's male divers lead the world rankings in three out of four events, with Mexico ranked first on 3-meter springboard. China's women lead the world rankings in all four events, and they have the top five women on 3-meter and the top three on 10-meter platform.
WATER POLO -- Serbia is the world's top-ranked men's team, followed by Hungary, Croatia and Montenegro. On the women's side, the U.S. is No. 1, followed by China, Spain and Australia.