An American yachtsman whose vessel capsized in heavy seas whipped up by tropical storm Cristobal says he felt like he was "in a washing machine" as his boat overturned and then righted itself in the swirling storm, tossing him about the cabin.

Cyril O'Leary, 66, of Fairhaven, Mass., was plucked from the North Atlantic by a Canadian rescue helicopter about 252 kilometres southeast of Halifax late Tuesday night.

The experienced sailor had been planning to travel alone across the Atlantic from Fairhaven to the Azores in Portugal.

He said he thought he could sail along the northern edge of Cristobal.