A 51-year-old Frenchman has embarked on a long-distance swim in shark-infested waters - a journey which will take him thousands of miles across the Pacific Ocean from Tokyo to San Francisco.

Ben Lecomte is set to cover 9,000km (5,600 miles) battling giant waves, jellyfish and the "Great Pacific garbage patch" - a large collection of plastic waste in the ocean between California and Hawaii.

The adventurer and environmentalist is hoping to become the first person to swim across the world's largest ocean.

"I'm very anxious to start right now," said Mr Lecomte, before he took to the water on Tuesday at 9am local time under warm conditions and a slight breeze. "It's very emotional for a lot of people here."

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. @Discovery pic.twitter.com/TPJlz4tbEY — Ben Lecomte (@BenLecomteSwim) June 4, 2018

His son and daughter joined him for the first 100 metres before rejoining well-wishers and family on the shore.


The swimmer is hoping to raise awareness of the plastic waste and ocean pollution blighting the water, with his support team hoping to carry out experiments throughout the trip, which is expected to take between six and eight months.

He will also wear a device to test levels of radioactive material from the Fukushima nuclear plant, which was hit by a tsunami in 2011.

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.

Image: Ben Lecomte as he set off from Japan

He is expected to shed more than 8,000 calories a day.

"The mental part is much more important than the physical. 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.

"When you don't have anything to occupy your mind, it goes into kind of a spiral, and that's when trouble starts."

Mr Lecomte, who previously swam across the Atlantic in 1998, admitted he would probably hit a "wall" after four to six hours of swimming.

Image: Mr Lecomte said the 'mental part' was more important the physical

He added: "I try to disassociate my mind from my body and everything that happens to my body - pain or cold, I try to put aside.

"I have a schedule of what I'm going to think about for those eight hours... it's always about keeping my mind occupied."

Although he vowed "never again" to take on a long-distance swim, he was inspired by his children to get back into the water.

"When I was little and I was with my father walking on the beach, I didn't see any plastic, or hardly any," he said. "Now every time I go with my kids, we see plastic everywhere."