In the 3-kilometer open swim off Robert Crown Beach in Alameda Saturday, Menlo Park resident Susan Preston beat out 291 other women for the overall championship with a time of 41 minutes, 33 seconds.
Jeff Erwin, 42, was the men's overall winner with a time of 39:06.
Teams in nine men's and women's divisions also finished a week of water polo play.
Among the winning teams were Team Vegas/Henderson (Women's 30-plus), Quebec Fusion (Women's 40-plus), Soda Mom's (Women's 50-plus), Imperial Sport (Men's 30-plus), Kazakhstan Masters (Men's 35-plus), The Olympic Club (Men's 40-plus), Santa Barbara (Men's 45-plus), Brisbane Barracudas (Men's 50-plus) and Norcal Alumni Blue (Men's 55-plus).
After the seventh and final day of swimming competition wrapped up Friday afternoon, 160 world records had been broken, bettering the previous tournament mark of 104 from four years ago.
Great Britain's Jane Asher, 77, continued a remarkable string of outstanding finishes at this tournament.
She broke the world record in five events (100, 200, 400 and 800 free and 50 fly) and has now captured first place in every event she ever swam at each of seven FINA Masters World Championships.
"I really had to get my pacing right as there were women on either side of me who pushed me and I had to be sure not to go out too fast," said Asher, a swimming teacher from London. "Whoever follows me is going to have some work to do. These records are made to be broken and they make me and others set our sights higher."
American Graham Johnston, 75, set eight world records of his own, including the 400 free with a time 18 seconds faster than the previous mark. Johnston also set records in the 100, 200 and 800 free as well as the 200 IM.
"For me it's the right distance as long as I don't panic in the first 100," he said.
55-year-old Santa Clara resident Laura Val broke six world records of her own in her first year competing in the 55-to-59 age group.
She was the 2001 Masters Swimmer of the Year after setting 21 world records and 26 national marks. She earned No. 1 rankings in 30 of a possible 53 events at age 49.
Other standout performances included four world records each for Susan Vor Der Lippe, 41 and Dennis Baker, 45.
Former three-time Olympian Gary Hall set his first world record with a time of 1:07.81 in the 100 back. He and son Gary Hall, Jr. are the only father-son duo in Olympic history in any sport to make three Olympic teams each.