The 82-year-old Weaver was taking part in The Original Baltimore Baseball Cruise aboard the Celebrity Silhouette cruise ship, which departed from Fort Lauderdale last Sunday with an itinerary that included stops in Cozumel, Grand Cayman, Jamaica and Haiti.
Cruisecritic.com, a website specializing in cruises and a gathering place for cruise-goers, reported that Weaver collapsed in his cabin and never regained consciousness.
Carolyn Spencer Brown, editor of cruisecritic.com, said Weaver was known to enjoy cruising, especially when he could be joined by Orioles fans.
"He really loved those cruises," said Spencer Brown, whose father, Bob Brown, worked with Weaver doing public relations for the Orioles for decades.
She said her father was "devastated" by Weaver's death.
Spencer Brown said theme cruises present a unique opportunity for fans to get up close to Orioles personnel.
"They're marvelous. It's the coolest opportunity, if you really love the Orioles, to cruise with players and staff," she said. "You really come to feel like you're part of something."
Weaver's death came near the end of the theme cruise and after a week of special events that included autograph sessions, casino night, a treasure hunt and a cocktail party. Other Orioles notables featured on the cruise included former pitchers Scott McGregor and Bill Swaggerty and sportscaster Fred Manfra.
The Celebrity Silhouette is a relatively new cruise ship having just been introduced into service in 2011. The 122,400-ton megaship carries 2,886 passengers at full capacity.
Spencer Brown said many of the newer ships have sophisticated medical centers on board. Some have what are essentially small hospitals — even morgues — that provide 24-hour care.
Spencer Brown, who grew up in the Baltimore area, said she was saddened by Weaver's death and her thoughts were with his wife Marianna.
"[At least] he was having fun and he was doing something he enjoyed," she said.