Thousands of boats packed the French Atlantic port of Les Sables d'Olonne to bid the fleet farewell.
More than 300,000 spectators lined the port and nearby coast to watch the boats from France, Japan, New Zealand, the United States, Britain, Ireland, Hungary, the Netherlands, Spain and Switzerland.
Kojiro Shiraishi, the first Asian to take part, wore a samurai costume on his Spirit of Yukoh to pay tribute to the crowd.
Meanwhile, Alan Roura from Switzerland, at 23 the youngest competitor, dressed up as the cartoon adventurer Corto Maltese.
But once the departure festivities were over, the rival navigators, all in 18.5-metre monohulls, had to quickly face up to a daunting battle against the world's major oceans, a lack of sleep and loneliness.
The Vendée Globe has so far claimed three lives while only 71 out of 138 vessels entered have completed the course.
The nine genuine contenders are all aiming to beat the 78 days, two hours, 16 minutes and 40 seconds set by the 2012-13 winner, François Gabart.
Organisers predict the winner could complete the "Everest of the Seas" -- 21,638 nautical miles (40,073 km) taking in the three great Capes -- Good Hope, Leeuwin and the Horn -- by about 20 January .
Welshman Alex Thomson, taking part in his fourth Vendée Globe, indicated that "if the forecasts are correct it will be tough for the boats without foils to be in the front group".
He and his rivals then headed out into the ocean and toward the Equator, which they are slated to reach in about eight days.
This Monday at 12.00pm GMT, British skipper Alex Thomson was leading, with Frenchman Jean-Pierre Dick and Breton Armel le Cléach'h following closely, while their boats passed the northern coast of Spain.