But despite the large crowds, with thousands turning out to watch fireworks and listen to music on the Esplanade on Saturday night, police reported no incidents from the well-mannered visitors.
"Extraordinarily well-behaved are the words to describe the American servicemen," Cairns police’s Sen-Sgt Michael Bishop said.
"We were expecting them to behave well and they did.
"Their standards of discipline are very high."
The off-duty servicemen enjoyed their last big night of R ’n R on Saturday partying at popular city night-spots such as the Woolshed, Gilligan’s and Rhino Bar, where bar staff donned sailor hats and painted the stars and stripes on their faces.
"All my bar staff made $200 or more each in tips just on that night alone," a Rhino Bar spokeswoman said.
"It’s not only the businesses that have done well but the staff as well."
The bar’s manager Ritchie Midson was among many who praised the visitors’ manners.
"They were really polite, good guys … they actually say please and thank you more than the locals," Mr Midson said.
Although officially the servicemen were warned not to frequent the city’s brothels, Bernie Lee Long, who co-owns the Forbidden Apple at Portsmith, yesterday said his bookings just about doubled over the past week.
Reinforcements even had to be called in from down south to keep up with demand, Mr Lee Long said.
"The young, blonde and busty ones were particularly in demand but they were all kept very busy," he said.
"I think they’ll be happy to have a few days off actually."