Aleksander Doba said on his Google+ page that he arrived in Florida late on Thursday after setting off from Lisbon on 5 October in the 6.4mwhite and yellow kayak he calls "Olo."
Doba posted a photo of himself sporting a foot-long greying beard and broad smile on his weathered face, arms raised in jubilation, after reaching the Florida coast.
"He said he's very tired because for the last three nights he didn't sleep with the crossing of the Gulf Stream," the adventurer's translator told The Daytona Beach News-Journal.
Doba, who also claims to have crossed the Baltic Sea by kayak, recounted navigating ocean swells and tempestuous weather during the 8,000km Atlantic journey.
He said he made a stop in Bermuda to have his kayak repaired.