Long-distance swimmer Ben Lecomte is set to swim through kilometres of the world's most polluted stretch of water to raise awareness about the overuse of plastics.

Lecomte, from France, will set off from Hawaii on Thursday, local time, to swim 555 kilometres through an area known as the Great Pacific Garbage Patch to California.

"The solution is in our hands, but we need to change how we use plastic": Distance swimmer Ben Lecomte will swim through a massive patch of plastic waste in the Pacific Ocean. Credit:Tom Powell

The patch, also known as the Pacific Trash Vortex, is a section of ocean that lies roughly halfway between Hawaii and California. Spanning 1.6 million square kilometres, its plastic waste is estimated to weigh 87,000 tonnes and contain more than 1.8 trillion pieces of plastic. It's a larger space than the entirety of South Africa, or NSW and Victoria combined.

"I've been doing open water swimming for a long time - and I've seen a big difference in those 30 years in plastics and microfibres that you find in the ocean," Lecomte said.