It took six grueling hours navigating the 30-mile ship channel. At nearly 900 feet in length, it was the largest cruise ship ever to dock at Mobile.
Galveston is the home port of the ill-fated ship, which lost power in an engine-room fire Sunday some 150 miles off Mexico's Yucatan peninsula.
A team of six investigators from the National Transportation Safety Board was in Mobile to look into what caused the engine room fire, NTSB spokesman Keith Holloway said Friday.
The NTSB was working with the U.S. Coast Guard and the Bahamas Maritime Authority, which will serve as the primary investigative agency. The Bahamian government was taking the lead because the Triumph is a Bahamian-flagged vessel and it was in international waters at the time of the fire, Holloway said.
Still, the NTSB could take information from the probe and use it to make recommendations for improving cruise ship safety, he said.
Carnival CEO Gerry Cahill apologized at a news conference and later on the public address system as people disembarked.
"I appreciate the patience of our guests and their ability to cope with the situation. And I'd like to reiterate the apology I made earlier. I know the conditions on board were very poor," he said. "We pride ourselves on providing our guests with a great vacation experience, and clearly we failed in this particular case."
Joseph and Cecilia Alvarez of San Antonio said some passengers passed the time by forming a Bible study group.
"It was awesome," he said. "It lifted up our souls and gave us hope that we would get back."
The company disputed the accounts of passengers who described the ship as filthy, saying employees were doing everything to ensure people were comfortable.
In a text message, Kalin Hill, of Houston, described deplorable conditions over the past few days.
"The lower floors had it the worst, the floors 'squish' when you walk and lots of the lower rooms have flooding from above floors," Hill wrote. "Half the bachelorette party was on two; the smell down there literally chokes you and hurts your eyes."
Passengers were supposed to get a full refund and discounts on future cruises, and Carnival said it would give an additional $500 in compensation.
"This is my first and last cruise. So if anyone wants my free cruise, look me up," said Kendall Jenkins, 24, of Houston. Bounding off the ship in bathrobes, she and her friend Brittany Ferguson immediately kissed the pavement at the Port of Mobile in Alabama.
Associated Press writers Ramit Plushnick-Masti in Houston, Stacey Plaisance in New Orleans, Bob Johnson in Montgomery, Ala., and Melissa Nelson-Gabriel in Mobile, Ala., contributed to this report.