Both Luiz Diniz and Sean Poynter are poised to battle for the gold medal as they each posted high heat totals on day three.

Long left hand waves lent themselves to a great day of competition with American Poynter scoring 16.10.

Brazil's Diniz finished on 15.8 and secured his place alongside Poynter in the main event final.

Australia's Harry Maskell and Brazil's Caio Vaz also qualified and are in search of their first International Surfing Association (ISA) golds in Riyue Bay.

The top two placed athletes from the main event finals will secure a medal position in the grand final, while the bottom two will head to the repechage final where they will get a second chance to advance to the grand final.

Maskell has never won gold, but claimed the silver medal in the event last year and has qualifying for the grand final in in his sights.

"I am really enjoying the competition here in Riyue Bay," said the Australian.

"Everything is going smooth and it's great that the swell has arrived too.

"All the athletes in the competition today are really high-end guys, so it was good to get a taste of the competition to come on the final day."

Both the men's and women's medals will be decided tomorrow.

In the women's SUP surfing competition, defending champion Shakira Westdrop scorched through the repechage heats to keep herself in the running for the grand final.

The Australian earned the three highest heat totals of the day with 14.33, 14.27 and 13.37.

Brazil's Nicole Pacello, New Zealand's Stella Smith, Spain's Iballa Ruano Moreno and Japan's Yuuka Horikoshi have all qualified for the women's main event final.

As the SUP competition comes to a conclusion, ISA President Fernando Aguerre looked forward to the prospect of a hard-fought final day.

"The world's best SUP surfers have been putting on a great show in excellent conditions at Riyue Bay," he said.

"Tomorrow the hard work, national pride and determination that we have witnessed all week will culminate with two world champions.

"We have past world champions in the mix, as well as new surfers who are looking to make a name for themselves on a global stage.

"The world champions will write history as the first to be crowned in Asia, after the ISA has crowned champions on four continents throughout the past seven editions of the event.

"This will truly be a historic moment for the ISA's development and governance of SUP."

The ISA has faced a legal battle with the International Canoe Federation, which also claims to be the governing body of SUP disciplines.