About 100 supporters waved as Laura and her father Dick left the southern Dutch harbor of Den Osse in her 38-foot (11.5-meter) yacht Guppy, bound for Portugal where she plans to leave her father and begin her circumnavigation attempt.
Last week, Laura won a legal battle when a court released her from the guardianship of Dutch child protection agencies. They had blocked her initial plan to depart at age 13 over fears for her safety and psychological health during the trip, which will likely take around a year.
"I can be sailing now, and that's great!" she told reporters Wednesday, sporting a skull-emblazoned black T-shirt.
Laura hoisted the black Jolly Roger-like flag of The Sea Shepherd Conservation Society above her red twin-masted ketch -- the same image she wore on her shirt -- before sailing out.
Laura, who was born on a yacht off the coast of New Zealand, has been working to counter objections to her voyage since the authorities stepped in last year. She got a bigger, sturdier boat, took courses in first aid and practiced coping with sleep deprivation. She also made at least one solo trip across the North Sea to England.
The Dutch court ruled that Laura's preparations were adequate and it was up to her parents to decide whether to let her make the attempt. Her mother, Babs Mueller, who is separated from her father, recently withdrew her opposition to the plan.
Her case has fueled a global debate over the wisdom of allowing ever-younger sailors to take on the tremendous risks of sailing the high seas alone.
If she completes the voyage, any record she claims would be unofficial and likely to be challenged. The Guinness' World Records and the World Sailing Speed Record Council have decided they will no longer recognize records for "youngest" sailors to avoid encouraging overly optimistic youths backed by ambitious parents from seeking a world record.
In June, 16-year-old American teen Abby Sunderland had to be rescued in a remote section of the Indian Ocean during an attempt to circle the globe. A huge wave snapped her mast and left her helpless until she was eventually rescued by a French fishing boat more than 2,000 miles (3,200 kilometers) west of Australia.
Her parents were sharply criticized for allowing her to undertake the trip -- a complete turnaround from the praise the family had basked in a year earlier when Abby's older brother Zac successfully captured the world record for youngest solo circumnavigator at age 17.
Three months ago, Australian Jessica Watson, completed a 210-day voyage on her 34-foot (10-meter) yacht, Ella's Pink Lady, around the world at age 16.
But while Watson remained at sea nonstop, Laura plans to stop at dozens of ports along the way to meet her family, rest, stock up and make boat repairs. She hasn't ruled out returning home to catch up on her studies if necessary before resuming her trip.
Laura conceded her trip "is a little bit different as the old ones, because they do it nonstop and I will do with stops."
Asked whether she was afraid of pirates in the Gulf of Aden, she said no, she expected to travel in a protected convoy through that area.
"Most people say it is a big problem, but there are so many yachts that will get in this water and then we will sail all together," she said.