By sunset local time (2300 GMT) yesterday, Jonathan Trappe was approaching Corner Brook, on the west coast of the Canadian province of Newfoundland and Labrador, satellite tracking websites indicated.
"In the quiet sky, above the great Gulf of St. Lawrence, travelling over 50 mph in my little yellow rowboat at 18,000 feet," or 80 kilometres per hour and 5,500 meters, wrote Trappe earlier on Facebook.
Trappe, a technical projects manager and balloon enthusiast from North Carolina, departed at dawn from Caribou, Maine to the strains of "The Star-Spangled Banner" and cheers from his ground crew who had spent the night inflating his craft's 370 balloons with helium.
Trappe, who has previously flown cluster balloons over the English Channel and the Alps, has said he expects his journey to take three to six days, depending on weather.
"I could literally land in North Africa, Portugal, Spain, France, the United Kingdom (or) all the way up to Norway," he told the Bangor Daily News in Maine back in February when he was finalising his plans.
His craft, with the US registration number N878UP, has been certified as airworthy by the Federal Aviation Administration.