Before French marathon swimmer Benoit Lecomte began his six-month-long attempt Tuesday to become the first to swim across the Pacific Ocean, he prepared for a number of possible challenges such as sharks, extremely cold water - and "plastic smog".
Battling sharks and jellyfish, the passionate environmentalist hopes his epic mission from Tokyo to San Francisco will raise awareness of plastic pollution in the oceans - an obstacle that could prove to be his most unsafe foe.
Mr Lecomte, who plans to swim eight hours a day, will eat, rest and sleep on a boat which will accompany him before being dropped off every morning to where he stopped swimming the previous evening.More news: Amazon Fire TV Cube puts Alexa in control of your home entertainment
For Lecomte, raising awareness of these issues is more important than setting any record. "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.
"Pollution of the ocean has a big impact", said the father-of-two, who will be gathering oceanographic and medical data for 27 scientific organizations, including NASA.
'When I was little and I was with my father walking on the beach, I didn't see any plastic, or hardly any.
"What is going to be hard is every morning going back in the water (because) you hit a wall, normally after 4-6 hours", he said of the mental challenge.More news: Macron, Trudeau support 'strong multilateralism' ahead of G7
"Now every time I go with my kids, we see plastic everywhere".
To keep the boredom at bay, and to perhaps stave off thoughts of just how far he still has to go before he passes beneath the Golden Gate Bridge, Mr Lecomte draws up a detailed schedule of what he will think about for each of the eight to 10 hours he will spend in the water during the epic swim.
After successfully completing the Atlantic swim, Lecomte vowed "never again" to set off on a long-distance sea journey.More news: Cecchinato enjoys life-changing moment at French Open