Stephanie Gilmore is in the box seat to claim a record-equalling seventh world surfing title this year but she knows her experience will count for nothing as the sport enters new waters on Friday.
California's Surf Ranch - an artificial wave designed by 11-times world champion Kelly Slater - will make its tour debut this week in a groundbreaking moment for the sport.
Surfers will complete runs like a Winter Olympic half-pipe competitor, meaning the usual priority rules, jockeying for position, lay days and general unpredictability of the ocean doesn't apply.
Gilmore enters with a slender lead over Lakey Peterson with three of the 10 stops remaining, knowing she could easily be run down in the Californian desert.
"It's nerve-wracking to know when you're surfing to the exact minute," Gilmore told AAP.
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"It's a new experience for everyone but there's a world title on the line, so there will be drama for sure.
"We'll see what happens ... maybe this event will shake things up, produce a brand new winner, it's so different."
Gilmore expects pint-sized teenager Caroline Marks to exploit the smaller barrels, while she also rates Carissa Moore's exploits on the artificial wave.
Brazilians Felipe Toledo and Gabriel Medina are one and two in the men's rankings, ahead of Sunshine Coast's Julian Wilson.
The Australian will have his work cut out in California to keep up with the South Americans, according to Gilmore.
"Felipe ... it's built for him and Gabriel's flow will be bananas," Gilmore said.
HOW A WINNER IS CROWNED
* Each surfer gets four waves across two runs (two lefts, two rights) with surfing order determined by overall series ranking.
* After the second run, surfers take their best right and left scores and are re-seeded in reverse order for a third run.
* After the third run the top eight men and top four women with the highest combined totals progress to the final.
* Each surfer gets another three runs in the final, with the highest-scoring left and right combination earning the crown.
