Ben Lecomte, a French long-distance swimmer, dropped into the water Tuesday at Choshi, Japan, and embarked on his attempt to become the first person to swim across the Pacific Ocean, BBC News reports.
Six years in the planning, the 5,500-mile effort is expected to take five to six months, with Lecomte swimming eight hours a day and covering an average of 30 miles daily, according to his website.
His route to San Francisco will take him through the Great Pacific Garbage Patch, an area three times the size of France where large amounts of garbage and plastic waste have collected, CNN reports.
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Lecomte will be accompanied by a specially outfitted support boat named Discoverer. He will take rest periods on the boat, but it will return him to his stopping point each day to make sure he swims the entire distance.
In addition to accomplishing a first, Lecomte said, he wants to draw attention to the problems of ocean pollution and climate change. A team of scientists plan to conduct research for 12 scientific institutions, including NASA and the Woods Hole Oceanographic Institution, while he is making his swim.
Lecomte is no stranger to feats of long-distance open-water swimming. In 1998, he swam 4,000 miles across the Atlantic Ocean. On that swim he encountered sharks and stingrays. This time, he said, he will be wearing a shark-repellent bracelet.
Earlier: Benoit Lecomte's swim across the Atlantic
One of the challenges will be making sure he has enough energy each day, and Lecomte said he intends to consume 8,000 calories daily.
More than six years of preparations have lead to this moment. Finally really to start my swim across the Pacific Ocean. #theswim#benlecomtetheswim watch the live stream of my departure on @Seeker Facebook. @Discoverypic.twitter.com/TPJlz4tbEY
— Ben Lecomte (@BenLecomteSwim) June 4, 2018
This article originally appeared on HuffPost.