Carissa Moore wins women’s final at U.S. Open of Surfing

The water wouldn’t cooperate much. It mostly stayed flat in the heat of a Southern California afternoon, providing scant waves here or there.

But Carissa Moore made do riding those few waves, and the last one Saturday took her to the biggest paycheck in the history of women’s surfing as she defeated Sally Fitzgibbons in the U.S. Open of Surfing women’s final at Huntington Beach.

The winner’s prize: $50,000 — a sizable increase from the previous amount of $20,000.

“It’s pretty amazing,” said Moore, who finished with a heat total of 12.50 out of 20 to Fitzgibbons’ 3.83.

The 17-year-old from Hawaii, who is the winningest competitor, men’s or women’s in National Scholastic Surfing Assn. history, said it came down to the final wave after she and Fitzgibbons turned down several early only to find that there weren’t many later.

“And then that last wave came in, and I’m kind of stoked I got that one,” Moore said of her final wave, which earned a score of 7.67 out of 10, sealing her win.

On the men’s side, eight surfers have a chance at the $100,000 first prize Sunday.

Huntington Beach native Brett Simpson, the defending champion, advanced with a huge round against Dane Reynolds, who scored a near-perfect single-wave score Thursday: 9.87 out of 10.

With two key waves Saturday against Reynolds — a 7.77 and a 9.37 — Simpson finished with a heat total of 17.14, more than enough to top Reynolds’ score of 7.77.

“It really wasn’t the perfect game plan … but it ended up paying off because I got a good score and he tried for big moves and ended up falling,” Simpson said.

Simpson will face Oxnard native Nathaniel Curran, who won the 2008 Open, in the quarterfinals. If Simpson wins, he will face the winner of the matchup between surfing legend Kelly Slater and Granger Larsen, who also advanced.

Ian Cairns, Simpson’s former coach and the current USA Surf Team coach, said if Simpson surfs smart against Curran, compiling good scores without being too risky, he’ll win for sure.

“But if he goes for broke, as he did against Dane, he could lose,” Cairns said.

Jordy Smith, Miguel Pupo, Jadson Andre and Mick Fanning round out the men’s field. Cairns said he thinks Andre and Slater will reach the final, a rematch of a World Tour final event in Brazil this year.

Andre, a World Tour rookie, upset Slater, a nine-time world champion, to win that event, and Cairns said the acrobatic Brazilian could do it again here.

baxter.holmes@latimes.com