A white boat about the size of a Cadillac labors out of the shadows beneath the 17th Street Causeway just south of Fort Lauderdale. The tiny vessel — flying the French national flag — crawls across the Intracoastal toward a small cement pier. As the craft coasts in, the man at the helm leaps to the dock. He's slight, with glasses, a head of dark curls, and a thin beard. His polo shirt, once light green, is gray from sweat. He ties his boat to a rusty hook and mumbles in French.

Jean-Gabriel Chelala, a 27-year-old engineer and freelance journalist, is arriving from a journey that began months ago, on the other side of the Atlantic Ocean. It wouldn't be a remarkable feat, except that his ride has no engine or sails. It doesn't even have oars. Chelala made the daunting 5,000-mile journey in a pedal boat.

He left Lagos, in southern Portugal, March 7. He pedaled alone for 107 days, eating military-style dehydrated meals and fish from the ocean, sleeping on a six-foot mattress in the small cabin, braving hurricane season and all manner of sea creature.

Info Frenchman pedals around world

After leaving Portugal, Chelala headed to Morocco and then west to the Canary Islands. Next, following the route used by Columbus more than 500 years ago, across the deep blue wonder of the open ocean, to Saint Martin. Then it was around Puerto Rico and into South Florida. Chelala averaged about two knots, pedaling for as many as 20 hours a day into strong winds. At one point, he says, he went more than two months without human contact.

But the journey from Portugal to Florida is just the second leg of a trip Chelala has been planning for more than two years. He's aiming to be the first person to circumnavigate the globe using only human power, he says.

It began in January, when he biked from his native Paris to Lagos. From Florida he plans to pedal across North America to the eastern tip of Alaska. There he'll get back into the pedal boat (which will be transported by truck) to cross the Bering Strait and then hop back on a bicycle to ride across Siberia and Europe, all the way back to rance. "I want to prove that we can do anything we want with just the power of humans," he says.

Waiting for him on shore in Fort Lauderdale is his father, Jean-Marie Chelala, who hasn't seen his son since he departed Portugal. Dad tells him to pose for the camera.

Chelala introduces himself to the handful of strangers gathered on the dock for his arrival: fans who've followed the trip on his blog, representatives from the local Rotary Club, a reporter, a photographer, and a few marina employees.

Designed by Guy Saillard, a French naval architect who specializes in building boats for extreme adventures, Cyclomer is 25 feet long and five feet wide, with a single chair in the middle. Solar panels line the sides. Beneath the front of the vessel, in the bow, Chelala keeps a desalinator ("it makes the water taste like plastic," he says with a smooth French accent), some electronics, and his garbage. In the cabin, at the stern, he has a small gas-powered hot plate, a bed, a GPS, and radio equipment. The pedals are attached to a propeller beneath the hull, and Chelala steers with a wheel on the starboard side. The whole thing cost him 100,000 euros, more than $165,000.

Ron Yentz, a manager at the marina, invites Chelala and his father inside for lunch. Chelala takes a seat at a table overlooking the water. What he's been craving most during his time at sea, he says, is "a very, very cold Coke, with lots of ice — it gets very hot in the middle of the ocean."

Asked how he feels about his son's daring trip, Jean-Marie beams. "I have three words: very, very proud."

So far, the most difficult aspect of the trip for Chelala has been the solitude. "It gets lonely," he says. "I miss my family. I miss being around people. You realize how much you need to talk to someone, anyone."

But loneliness was far from his only challenge. Just 20 miles off the coast of the Canary Islands, as he slept in the cabin, something large and powerful struck the bottom of the boat, lifting it out of the water and jarring him awake. When Chelala began pedaling the next morning, the steering didn't respond. He put on goggles, jumped into the water, and went down to examine the underside of the boat. "When I put my hand down to feel the rudder," he says, "I had a, a — how do you say? — a heart attack." The large fin beneath the boat that helps steer was completely gone. He says he took the boat back to shore by pedaling, jumping out, pushing it in the right direction, and then jumping back on.

"I think it must have been a large whale," he says. Within a week, though, he had a new rudder and a renewed passion to pump his calves across the current.

Early in the cross-Atlantic journey, four small fish began following his boat. Soon he was talking to them, naming the quartet: Andy, Charlie, Bobby, and Teddy. "They thought I was the mother," he says. They were small when he first saw them, but as the weeks passed, he says, they grew to three times their original size.

Every person at the dock eventually gets around to asking Chelala the obvious question: Why do you want to pedal around the world?