TARPON SPRINGS — After kayaking nearly 40 miles in one day, the last thing Mary Mangiapia wanted to do was tow some stranded jet skiers to shore."I had no choice," said the 28-year-old from Tampa who hopes to be the first woman to complete the 1,500-mile Florida Circumnavigational Saltwater Paddling Trail. "But they were stranded and needed help."The man and the woman told Mangiapia, who started her expedition Sept. 6 near the Alabama border, that their personal watercraft broke down Monday afternoon. They spent the night on a sandbar and tried to flag down passing boaters all day Tuesday off of Tarpon Springs. "When I found them that evening they were trying to swim for it," Mangiapia said. "So I helped get them to a dock then kept going. It just goes to show … you never know what's going to happen out on the water."Mangiapia, who recently received a master's degree in microbiology from the University of South Florida, has braved lightning storms and black bears so far on this trip that will take her down the Gulf Coast, across the Everglades, up and back along the Florida Keys and then north up the Atlantic Coast."I am giving myself 100 days to complete the trip," she said. "I hope to be finished by December. This is a present to myself after working so hard in school."The Circumnavigational Trail, or "CT" as paddlers call it, is to kayakers what the Appalachian Trail is to hikers. It begins at Big Lagoon State Park near Pensacola and traverses 20 national parks, seashores, wildlife refuges and marine sanctuaries, 37 Florida aquatic preserves and 47 Florida state parks, along with numerous local parks and preserves, before ending at Fort Clinch State Park near the Georgia border."It has been kind of crazy," said Mangiapia, who started paddling when she was 9. "I have a lot of bad weather. I had one day when the lighting was literally striking the beach where I had pulled over to sit out the storm."Mangiapia, who grew up in Venice, is no stranger to adversity. In 2012, she completed WaterTribe's Ultimate marathon, a 60-mile race from Fort De Soto Park to Cape Haze.The following year, she finished the Everglades Challenge, an unsupported, expedition-style adventure race for kayaks, canoes, and small boats that begins at Fort De Soto Park and ends in Key Largo. The distance is roughly 300 nautical miles, depending on the route the paddler chooses.There's a time limit of eight days. All contestants are required to sign a waiver and read a warning: "The physical demands of the race, combined with sleep deprivation, heat, cold, water dehydration and exhaustion, often cause participants to become disoriented. Amnesia, hallucinations, hypothermia and other debilitating conditions are not uncommon."Andy Bartley, Mangiapia's training and paddling partner, said the race pushed his friend to her limit. "Her seat broke and she was in so much pain, she was almost incoherent," he said. "But she powered through it and kept going. She's one tough chick."Mangiapia has paddled most of the way by herself, but there have been stretches where friends have met her and tried to keep up. "It is hard to find somebody who is willing to paddle 30 or 40 miles in one day," she said.When possible, she stays with friends along the way. But most nights, she camps by herself on a barrier island or in a park."I had to sit out the weather for a couple of days and found a great private campground in Panacea," she said. "The last morning I was there I was up early, leaving the restroom when I came face to face with a black bear."The animal ran off, but only after giving Mangiapia the scare of her life. "In general, people have been great," she said. "It seems like everywhere I turn, somebody that I have never met before is trying to help."Mangiapia is paddling an EPIC 18X, the same kayak that the Tampa Bay Rays recently bought for Yankees star Derek Jeter upon his retirement. "It is very fast and stable," she said. "I am only a day or two behind schedule.''The Department of Environmental Protection has done an excellent job planning the Florida Circumnavigational Saltwater Paddling Trail. With campsites and other lodging located about 10 to 15 miles apart, even a novice can plan and complete an overnight kayak/camping trip.The state Web site (dep.state.fl.us, follow the links to Greenways and Trails) is a good place to start. Buy a chart book for the section you plan to paddle. A minute of preparation can save you an hour on the water.