PROFESSIONAL distance swimmer Ben Lecomte has set off from Japan to San Francisco in an attempt to become the first person to swim across the Pacific Ocean.

Lecomte left at 8am local time on Monday from Choshi, which is north east of Tokyo in neighbouring Chiba prefecture, spokesman Alexandre Borreil said.

The 51-year-old Frenchman is expected to swim eight hours daily on a journey that could take six to eight months and will cover about 8000 kilometres (5000 miles) – including a 1000-mile section through a floating mass of rubbish, known as the ‘Great Pacific garbage patch’.

“For the moment we know he left and everything went well,” Borreil said.

Lecomte completed a similar swim in 1998, becoming the first person to swim across the Atlantic without a paddleboard.

The aim of the swim is to raise awareness of pollution in the world’s oceans.

Scientific teams will accompany Lecomte, studying plastic pollution, mammal migration and the effect of extreme endurance events on the human body.