On Long Island Sound (CNN) -- On Friday morning, I boarded a leaky oyster boat in Connecticut with a captain who can't swim. Our destination: Manhattan, 84 miles down the coast. Mission: don't drown get world leaders to act on climate change. If anyone can accomplish that herculean task it should be Bren Smith, a 42-year-old oysterman off the coast of Branford, Connecticut, who has become a sort of reluctant poster boy for doing something about the crisis instead of just talking about it. Bren's oyster beds were wiped out twice by hurricanes, once by Irene and then, a year later, by Sandy. Warming waters and ocean acidification aren't helping his business model, either. But instead of giving up, he's currently helping to pioneer new techniques for "ocean farming," growing, among other things, kelp seaweed for use in pasta, martinis and biofuel.
@highlight
Hundreds of thousands are expected at the People's Climate March on Sunday
@highlight
The event is billed as the biggest climate change demonstration to date
@highlight
Among them will be Bren Smith, an "ocean farmer" in Connecticut
@highlight
CNN's John Sutter rides with Smith by boat from his farm to New York
Three days after @placeholder hit, he told me, he got online and started researching alternative methods of oyster cultivation -- and new crops to "farm" in the ocean.