The Celebrity Mercury docked about 1:30 a.m. after an 11-day cruise and passengers began disembarking the ship shortly after dawn.
Celebrity Cruise spokeswoman Cynthia Martinez said at the height of the outbreak earlier this week 413 of the more than 2,600 passengers and crew came down with intestinal ailments. Celebrity Cruise is owned by Royal Caribbean Cruises Ltd.
An extra doctor and two nurses came aboard in St. Kitts in the Leeward Islands and sailed on the Mercury back to Charleston.
The Centers for Disease Control and Prevention said tests showed the outbreak was caused by norovirus, which can spread quickly in closed quarters.
There were two outbreaks of norovirus, which causes stomach flu, last winter on the Celebrity Mercury, according to the CDC Web site. In all, the agency investigated 15 outbreaks of gastrointestinal illnesses on cruise ships calling at American ports last year.
Sarah Bennett, 22, of Columbia, said the crew did a great job.
"They would not let you touch anything. Even the silverware they handed to you. They did everything," said Bennett. But, she added, "we were ready to get off."
Kenneth Thompson, 71, of Concord, N.C., came down with the virus and had to stay in his room for 24 hours in isolation.
"It's just one of those freak things that happens," said Thompson, who has been on five previous cruises.
The Celebrity Mercury was to be cleaned, as was the South Carolina State Ports Authority Passenger terminal, before 1,900 new passengers board the liner for another cruise.
The start of that cruise was delayed until 5 p.m. today to give crew members more time to sanitize the ship.
"The extra time we are taking to sanitize the ship will help prevent any illness from affecting the next cruise," Celebrity Cruises president Daniel Hanrahan said in a statement.