LONDON — Drifting in the ocean in a sailboat at the mercy of winds and currents would be a nightmare for many. But a 71-year-old Frenchman with a taste for adventure has found a new way to conquer the Atlantic Ocean: in a barrel.

The adventurer, Jean-Jacques Savin, set sail on Wednesday from El Hierro, the smallest of the Canary Islands, the Spanish archipelago west of Morocco. He will attempt to reach the Caribbean with only ocean currents and trade winds propelling his capsule, according to a Facebook page set up to document his project, where he plans to post daily updates including GPS coordinates tracking the journey.

Many people have crawled into barrels to go over Niagara Falls, with some surviving, but no one has been known to cross the Atlantic in a barrel made of plywood.

Mr. Savin, who hails from the oyster-farming town of Arès, in the southwest of France, hopes to achieve the feat in about three months in an orange barrel-shaped capsule about 10 feet long and 6 feet 8 inches wide. It’s smaller than a pickup and held upright by a concrete ballast.