John Maas spent years buying and outfitting a 17-foot aluminum boat called the Superskiff 1 so he could take customers fishing for sea trout and flounder in the Gulf of Mexico.

But before the Mississippi captain could make his first charter trip in 2010, the BP Deepwater Horizon drilling rig blew up 120 miles (193 kilometers) to the south, killing 11 people and sending many millions of gallons of oil into the sea.

As for many along the Gulf coast, the disaster changed Maas’ life. Fishing stopped when oil contaminated the water, so he used his boat to help clean up the spill. It was nasty work under oppressive, humid heat in oily water and around the chemical dispersant Corexit deployed in massive quantities to break up oil.

Maas said the Corexit smelled like burning brake fluid and caused his eyes to water and skin to burn. “You were coughing and things like that. It’s like tear gas almost,” he said in an interview.