An environmental activist jumps back into one of the city's most contaminated waterways to make a point about pollution. NY1’s Na’eem Douglas filed the following report.

It's the perfect fall day to go swimming in the Gowanus Canal - said no one ever - except Christopher Swain.

“They say I'm crazy,” he said.

There is a method to Swain's madness though. He is not going for a swim in one of the country's most polluted waterways for fun. He is doing it to make a point.

“The reason I'm doing it - I'm a swimmer, I like clean water - I want this whole waterway to be safe enough for swimming,” he said.

Making that point is something that has taken a lot of training and preparation. On Earth Day, Swain swam nearly two thirds of the waterway, but did not finish because of weather.

“I have to come up with a strategy to keep the water off my skin,” he said. “The big deal there is a dry suit that keeps the water off me up to my neck. Then water barrier gel to keep my exposed skin from absorbing water. Swim cap, goggles, earplugs - the whole thing.”

With his plan set, there wasn't anything left but to hop in. His canoe escort picked him up at Union Street Bridge and took him back to just in front of Butler Street, the offical start of the canal - anything less would be cheating.

A crowd gathered to watch Swain breast stroke his way through the murky green waters of the Gowanus, including a young supporter who wondered if the pollution might end up giving the swimmer superpowers. He wondered what power he would need to make the trek.

“I don't know what power I'd get,” Swain said. “Maybe the power not swallow the water even though it's in my mouth.

Swain’s swim is also serving another purpose. During the trip, he took water samples and he'll be bringing those samples back for local grade school students so they can study the Gowanus.

He says he wants to swim in the Gowanus again, but only when it has been cleaned up. He admits that will take some time.