As many as 3,500 spectator vessels lined Chesapeake Bay as the Volvo Ocean Race sixth leg began from Annapolis.
An armada of spectator boats surrounds Pirates of the Caribbean
The figure surpassed the 2,000 boats which assembled for the start of the race in Vigo, Spain, last November.
Thousands more people took up vantage points on the Chesapeake Bay Bridge where traffic came to a standstill.
ABN Amro One skipper Mike Sanderson will be out to maintain his grip on the lead in the 400m-mile sprint to New York which will take around 40 hours.
Speaking ahead of Sunday's start, the Kiwi predicted: "It's going to be very tricky on either end.
"It figures to be rather light and fickle getting out of the Chesapeake, and the harbour finish in New York will bring its own challenges.
"It's going to be a battle the whole way, and it won't be decided until the boats are berthed in North Cove.
"We are going to work very hard from start to finish. I don't think the crew will get much sleep."
The winner of the leg earns seven points, awarded for waypoints and in-port races.
ABN Amro One leads with 63.5 points from Spanish boat Movistar on 44 and Paul Cayard's Pirates of the Caribbean on 41.5.
New York is considered a "pit stop", which means the seven yachts must remain in the water and cannot take on any new gear or supplies.
The fleet will begin leg seven to Portsmouth, England, on Thursday, with each syndicate leaving New York in the order it arrived.
The leg six winner will get a head start on the runner-up finisher by the same amount of time that it beat that boat into port.