A surveillance camera on the Norwegian Pearl ship showed someone falling overboard at 8 p.m. that night, authorities said. About eight hours later, Raymond Seitz reported his wife, Jennifer, missing.
Coast Guard and Mexican naval vessels conducted an "exhaustive" search through the weekend covering more 4,200 square miles off the popular resort town of Cancun, where the Norwegian Pearl had just visited. Mexican authorities said they would continue their search for another 48 hours.
Norwegian Cruise Line said it is "cooperating fully" with the FBI.
"Our thoughts and prayers are with the family and friends of the guest during this difficult time," the company said in a news release.
Raymond Seitz has not been charged with any crime, authorities said Monday.
His wife was a freelance writer, having written articles for The Tampa Tribune, Florida Today, and penned a story for an online site titled, "Battling the Bulge Onboard," about how not to gain weight while onboard a ship. On her Web site, Seitz described herself as an "avid traveler and an amateur chef." She was previously a reporter for Florida Today, a newspaper in Melbourne.
A passenger on the ship said Seitz and her new husband stood out among the vacationers onboard with "large and raw personalities."
Many of the passengers saw them as contestants on an on-board game called "The Not-So-Newlywed Game," modeled after a 1960s TV quiz show. The game was also carried on the ship's closed-circuit TV channel.
"Very likable,' Walker said. "We're just really shocked now, to be honest."