FORT DE SOTO PARK — Shane Perrin doesn't talk much. He just paddles.The 37-year-old former USF cheerleader has completed three of the most grueling races in the world — the 179-mile La Ruta Maya on the Belize River, the 260-mile Texas Water Safari on the San Marcos and Guadalupe rivers and the 340-mile Missouri American Water — on a standup paddleboard.Now, 12 years after undergoing a life-saving kidney transplant, the Missouri man has his sights on the 300-mile WaterTribe Everglades Challenge, a weeklong trek down Florida's southwest coast that takes paddlers along the edge of the Everglades."I don't know what really to expect," said Perrin, who was a few credits shy of graduating when he was diagnosed with a hereditary kidney disease. "But I've been through a lot and feel like I am ready for anything."The Everglades Challenge, as the race from St. Petersburg to Key Largo is now technically called, can take eight days to complete. For the first half of the race, paddlers in canoes, kayaks, a variety of small boats and paddleboards can stick to the relative safety of the Intracoastal Waterway.But once they round Cape Romano near Marco Island, all bets are off as paddlers enter Florida Bay and the wilds of the Ten Thousand Islands.It can take a couple of days to make it from the check-in at Chokoloskee to Flamingo. Thinking back to that first race in 2001, it was that stretch of water on the mud flats where I began to hallucinate and had to be shaken back to sanity by my paddling partner, Jon Willis.The start was rough. Several of the 27 teams didn't make it across Tampa Bay. Willis and I flipped our tandem kayak off Egmont Key but climbed back in. After 6 days, 7 hours, 22 minutes of extraordinary adventure we made landfall in Key Largo, one of just nine teams to finish that inaugural race. The ordeal wiped me out, and I only did half the paddling.So I can't imagine how Perrin, who goes by the nom de guerre "Stand Up Guy," is going to make it all the way by himself. But Perrin, the father of two, is a battler. The former high school wrestler has seen his share of adversity. He is the first paddler to complete all of the previously mentioned races on his feet."People have tried before to do this race on a SUP," WaterTribe founder Steve Isaac said. "This could be a record year."More than 100 vessels have registered for this year's event, which begins at 7 a.m. Saturday from Fort De Soto Park's east beach. Some of the paddlers will be entered in the Ultra Marathon, a 62-mile section that finishes in Englewood.After checking in, those entered in the Everglades Challenge will continue, stopping at Chokoloskee/Everglades City, then Flamingo before reaching Key Largo."I am a little worried about the Everglades," Perrin said. "Not sure how I'll be able to carry enough water."WaterTribe racers must be completely self-supported in only human- or wind-powered craft. That means they must carry all of their food, water and safety gear, and can only supplement their supplies with what they can buy along the way."I don't carry much … maybe 50 pounds of gear," Perrin said.He subsists on SPIZ, an endurance energy drink: "It is actually pretty good. I don't need much to survive."Perrin, who works in the parks department in Missouri, has only been paddling for three years. He started off standing up in his canoe and using a paddle he made himself."When I got my first board I was hooked," he said.For this challenge he will be paddling a new, custom-made 18-foot Pau Hana paddleboard."The board looks fast, but most of my races have been on rivers," he said. "Dealing with the ocean is a whole different thing."Perrin declined to predict if or when he will finish the Everglades Challenge. But one thing is for sure, he said: "It will be an adventure."