French marathon swimmer Benoit "Ben" Lecomte prepares himself in Choshi, Chiba prefecture on June 5, 2018 as he takes the start of his attempt of swimming across the Pacific Ocean.
His latest swim began in Japan with the goal of reaching San Francisco in about six months. In the Pacific, the biggest accumulation of plastic smog is about the size of Germany, France, and Britain combined and Lecomte will swim right through it.
Scientific teams accompanying Lecomte, including NASA, will collect more than 1,000 water samples and study plastic pollution, mammal migration and the effect of extreme endurance events on the human body.
The expedition's first mate, Tyral Dalitz, told ABC the team wanted to dispel a myth about the garbage patch.
"In reality the truth is much worse - the ocean is now filled with microplastics ..."
In particular, they are anxious about microplastic particles, bits measuring no more than two-tenths of an inch (5 mm), which come from large plastic trash that has fragmented into smaller pieces or microbeads in products like facial soap, body wash and toothpaste.
Lecomte set off from Tokyo at 9am local time.
It was becoming a father that inspired the Frenchman to take up his cause. "Now, everywhere I go on the beach, I see plastic everywhere".
"Now every time I go with my kids, we see plastic everywhere", added Lecomte, who will also wear a device to test levels of radioactive material from the tsunami-hit Fukushima nuclear plant.
While the swimmer is expected to burn more than 8,000 calories a day, Lecomte says the hardest barrier is in his head.
"To do the physical aspect of it, yea, it is hard, but what is much more hard is to be in that very hostile environment, and the mind has to be super strong", he said. "You have to make sure you always think about something positive or you always have something to think about", he said, reflecting on the task ahead.
And he would know. His words as he left the water?