BROOKLYN - A clean water advocate who says he's sickened by the amount of pollution in New York City waterways is hoping to shed light on the issue.

Christopher Swain has taken on numerous swims through polluted waters, including a dip in the Gowanus Canal and Newtown Creek near Greenpoint last year. 

On Thursday, he plans to start swimming in Montauk, at the end of Long Island, and swim the entire length of the Long Island Sound to the East River and conclude his swim at Pier 4.

Swain says health officials routinely advise him against going in the water, but he ignores those pleas so he can promote his cause.

Swain's plan is to swim four to six hours a day, taking some breaks in between. He hopes to complete his swim by the end of October.