UPDATE (Monday, Aug. 5, at 3:25 p.m. ET) — The men's and women's Olympic surfing finals are DELAYED, with a potential start time now scheduled for Monday, Aug. 5., at 4:30 p.m. Assuming the competition is on, the semifinals will be followed immediately by the medal finals.

The surfing quarterfinals wrapped up and the final day of competition is set, with semifinals and medal finals scheduled to start on Saturday, Aug. 3, at 1:00 p.m. ET.

It's been a thrilling competition so far that's taken the sport to new heights, and the final day should be no different with an intriguing mix of favorites and underdogs still in the mix. Here's what you should know before the surfers paddle out for the final time in Teahupo'o.

Local boy looking to become a legend

Headlining the first men's semifinal is France's Kauli Vaast. However, it may be more accurate to refer to him as Tahiti's own, as the surfer is a local to the island and is hitting the waves at his local break. At a venue as unique as Teahupo'o, that gives him a massive advantage if the waves are pumping like they were for the men's third round. The reef is famous for its monstrous barrels that form out of nowhere, giving a big boost to surfers who are well equipped with the ability to read and anticipate the oncoming sets. Vaast has been surfing these swells since he was a kid and has loads more experience here than any other competitor. If the sets look like they did for the third round, he may be the favorite to take home the gold. He is still a strong threat even if the waves are mild, as he out-dueled his teammate, Joan Duru, in the quarterfinals by creating stellar scores out of mediocre conditions.

Trying to put an end to Vaast's run will be Peru's Alonso Correa, who has already downed some tough competition. He won his heavyweight heat in Round 1, defeating Tokyo silver medalist, Kanoa Igarashi, and medal hopeful, Filipe Toledo, of Brazil. The Peruvian has won in all different ways this tournament, blowing out some of his competitors and just squeaking by others. The hometown hero will be his most difficult test yet.

Medina aims to make his iconic photo historic

Brazilian Gabriel Medina is already a three-time world champion, but he'll hope to be an Olympic champion by the time the sun sets Saturday night. Medina has probably become the most popular surfer in the world during this tournament. In Round 3, he roared through a gorgeous barrel, throwing up ten fingers on the exit to call for a perfect score, and then soared off the lip and put up a No. 1 pose. Medina entered the Olympics as arguably the best surfer in the world and one of the favorites to take home the gold medal. He wants to cap off his storybook Olympics with the weight of that gold medal hanging around his neck. 

Standing in his way is Australia's Jack Robinson, a force to be reckoned with in his own right. After losing in Round 1, Robinson dominated Peru's Lucca Mesinas in Round 2, and then knocked off the other pre-tournament favorite, Team USA's John John Florence, in a Round 3 heavyweight clash. In the quarterfinals, he won another tight contest against his teammate, Ethan Ewing. Robinson entered the tournament as one of the best surfers in the sport and has run through a gauntlet to make it to the final day. 

Marks trying to keep gold in the USA

Entering the competition, any one of the U.S. surfers would have been a great pick to take home a gold medal. Five entered and now just one remains: Caroline Marks. Marks is already a superstar at just 22 years of age. She placed fourth in surfing's Olympic debut in Tokyo and has been on a meteoric ascent ever since, culminating with a world title last year. She now looks to add an Olympic gold medal to her trophy case and join American teammate, Carissa Moore, as the only gold medalists in women's surfing history. Her competition thus far has not been very exciting; that's because she has taken care of business with ease in every round of competition. The surfer has just two more business trips left before her Olympic legacy is cemented.

Trying to put an end to Marks' Olympic run is Joahnne Defay, who has been one of the best stories of the tournament. In Round 1, Defay took a scary fall, wiping out on a massive wave and hitting her head on the shallow reef at Teahupo'o. As she paddled back out to the lineup, she was forced to go get checked out by the medical team as blood ran down her face. She wound up losing her first-round heat, but since then has been unstoppable. It would have been understandable if she was hesitant after the injury, but she has been the complete opposite. From the second the horn blew to begin Round 2, Defay has charged fearlessly onto the biggest, meanest waves Teahupo'o has to offer. She has absolutely taken some more spills along the way, yet she has also tamed the beastly swells in three amazing performances that has led her to the semifinals. In the quarterfinals, she bounced the reigning Olympic champion, Carissa Moore, and will be looking to finish off the Americans en route to a gold medal on Saturday.

Hennessy hopes to bring Costa Rica its second gold

Costa Rica has only four medals in its Olympic history and just one gold. Brisa Hennessy can add to that total on Saturday. In Round 1, she put on a dominant showing. One of the surfers she took down in that first round was France's Defay, who she could meet again for a rematch in the finals. She then took down Portugal's Yolanda Hopkins in Round 3, clinching the win with a clutch barrel-ride, the best of the day so far. Finally in the quarterfinals, she found a different way to win, knocking off Brazil's Luana Silva in a tightly contested, low-scoring affair where she just scraped past. She needs to find two more wins in her to bring another gold back to her small island home.

The first obstacle she'll have to face is Tatiana Weston-Webb. The Brazilian lost in Round 1, when she found herself in the most stacked heat of the entire competition with world No. 1, Caitlin Simmers, and World No. 4, Molly Picklum. After fighting her way through Round 2, she got revenge against Simmers in statement fashion, winning by a gigantic margin in Round 3. Hours later, she grinded out another victory versus Spain's Nadia Erostarbe. The Brazilian also scored a perfect 10 in Teahupo'o at the WSL Tahiti Pro earlier this year. She has not yet been able to find that same magic, but could have some tricks up her sleeve for the final day.