There's only a hair of difference between fearless and crazy. Vivian Tyler, 39, is a good example.
She wants to sail to New Orleans down the Tennessee River and the Tennessee-Tombigbee Waterway, which runs to the Mobile Bay.
Here's the problem: Vivian only has a few hundred dollars, little river experience and no coherent plan for arriving in Louisiana in one piece. She's literally a drifter, although she says her home is in Cosby, Tenn.
Since Thanksgiving, Vivian has been pinballing down the Tennessee River in a sailboat she bought for a dollar. Along the way she's bobbed along riverbanks, getting stuck, making friends, braving locks and stirring disbelief among those she meets.
She reminds me of the Jamaican national bobsled team at the 1992 Winter Olympics.
When I caught up with Vivian, she was docked at Ross's Landing and had befriended Mary Burton and her husband, Chris, who own a local printing company.
When we talked, Vivian was wearing a denim jacket over a James Dean T-shirt. She has a commanding handshake and her palms are rough from handling rope. Oddly, she looks both young and old for her age; pretty and tired at the same time.
The Burtons are avid boaters and adopted Vivian for a few days while she was here. They gave her hot meals, let her wash clothes at their house and tried to educate her about the risks of the river.
As we talked, Mary confronted Vivian: "I think you're crazy."
"Thank you," Vivian replied.
And there, in a nutshell, is the fascinating part about this unlikely friendship. Caution vs. impulse. Planning vs. audacity. Security vs. reckless abandon.
Mary and her husband yearn to take their 36-foot Carver Sedan Bridge boat on a loop through the Gulf of Mexico. They have been talking about the trip for years, waiting for the perfect time when career and family obligations retreat.
Vivian, on the other hand, is a self-described "hippy chick." She bought a leaky, 25-foot sailboat with an eight-horsepower outboard motor and set out immediately for New Orleans.
She paid a marina manager a single silver dollar for her boat, which had been abandoned years before by its owner. Vivian has no problem with a Huckleberry Finn approach to river adventure.
"The sound of a sailboat is the sound of freedom," she said. "I love to see new places. I love to be on the move. It feels good."
Since leaving Blue Springs Marina on Watts Bar Lake in late November, Vivian has banged up her bow rail, broken her navigation light, gotten her keel stuck five times and called for a tow boat twice.
Along the way, people have rushed to help her -- mostly men apparently fascinated (and shocked) by her inexperience.
"Everybody has called me crazy, and I completely agree," Vivian said.
She hasn't had a job for 17 years, she said, and freedom is a personal creed. She sees life in suburbia as a "nightmare."
Mary, on the other hand, is alarmed by the fact that Vivian has no depth finder, no reliable heating source and -- get this -- no bathroom on her boat.
"We would like for her to stay [in Chattanooga] until her boat is provisioned," Mary said. "[Vivian's] a smart cracker, but I want her to be safe."
Vivian has nothing but the river current to give her direction. Mary plays by the rules and bides her time for the fun part of her life to start.
Meanwhile, they seemed a little envious of one another. It's as if they realize there is risk in both life directions, yet they are stuck in a comfortable current.
And the river rolls.
Contact Mark Kennedy at firstname.lastname@example.org or 423-757-6645. Follow him on Twitter @TFPCOLUMNIST. Subscribe to his Facebook updates at www.facebook.com/mkennedycolumnist.