1 Dies as Anti-Castro Flotilla Loses Vessel in Rough Seas : Cuba: Sinking dumps at least 45 people into shark-infested waters. Tragedy forces 24 other boats to turn back to Florida.

A controversial protest against Fidel Castro turned into a debacle Saturday when one of 25 boats carrying demonstrators toward the coast of Havana sank 10 miles away from Key West, Fla.

At least 45 people were dumped into six-foot-high seas in the Florida Straits, where they were left treading water and clinging to debris for up to an hour before being rescued by the U.S. Coast Guard and other boats in the flotilla.

One man died, apparently of a heart attack, after being airlifted to a Key West hospital.

“It was very scary,” said Sergio Rioseco, 50, one of the survivors of the Sundown Two, a 60-foot shrimp boat that sank quickly. “We saw sharks all around.”

Organizers called off the demonstration planned by Cuban exiles, and the flotilla returned to Key West, flying Cuban flags at half-mast.

Back on dry land, Ramon Saul Sanchez and other protest leaders considered rescheduling the 90-mile trip for today but were discouraged by Coast Guard officials. “The Coast Guard stated it would be dangerous. The weather is not promising, with six- to eight-foot waves,” Sanchez said.

In response to the Sundown Two’s distress call, the Coast Guard dispatched a cutter, a 41-foot utility boat and four helicopters.

“The boat was in very bad condition,” said Rioseco, a Miami real estate agent who left Cuba in 1954. “When the pump stopped, the boat started sinking, and within 15 minutes we found ourselves in the middle of the ocean.”

All aboard were wearing life jackets, Rioseco said, including the man who later died, identified as Lazaro Gutierrez, 59. “I rode down to Key West with him, and he told me he had a [heart] bypass operation. He also told me he had a bad feeling about the trip and that he couldn’t swim. But he wanted to go.”

Even after being thrown into the ragged seas, Rioseco said, the anti-Castro fervor of the participants was so high that the group began chanting “No Castro, no problema” while praying for rescue.

The flotilla had drawn the attention of State Department officials earlier in the week after sponsors conducted evasion and life-saving drills in rubber rafts that organizers hinted might be used to violate Cuba’s 12-mile territorial limit.

During a similar high-seas demonstration July 13, two private planes piloted by exiles buzzed Havana and a boat called the Democracia was rammed by a Cuban gunboat after it entered Cuban waters.

Sanchez vowed that this flotilla would respect the 12-mile boundary. The demonstrators’ goals, Sanchez said, were to hold a prayer service and throw messages about human rights overboard, contained in plastic milk jugs that the protesters hoped would float to the island.

The Democracia again led the flotilla out of Key West just after dawn Saturday, but in the blustery weather in the Gulf Stream, the protest did not get far. Rioseco said the chartered Sundown Two, trailing most of the other vessels, began taking on water within the first hour of what would have been a six-hour journey toward Cuba, and that one of two bilge pumps on the vessel soon failed.

Aboard another flotilla vessel was the president’s estranged daughter, Alina Fernandez Revuelta, who defected in 1993 and now lives in Georgia. “The experience was marvelous,” said Fernandez, who has not been previously active in political actions. “I’m sure the next one will be a complete success.”

In Washington, State Department spokeswoman Phyllis Young said a command post set up to monitor the flotilla was shut down after the protest foundered. “The death was a very tragic situation,” she said.

Also in Washington, a spokesman for the Cuban government, Jose Ponce, said of the flotilla calamity: “I think this is the cost of impudence. They were trying to prepare to stage a provocation of Cuba. They were preparing that despite the risk of accidents like this one. They didn’t pay any attention to warnings from the Cuban government, from the U.S. government.”

Many in Miami’s Cuban American community criticized the protest as a thinly disguised attempt by anti-Castro hard-liners to provoke an incident between the United States and Cuba. After the July incursions, Castro had promised to shoot down or sink any violators of its territory. This week the Cuban Communist Party newspaper, Granma, called the demonstrators from Miami “floating gangsters.”

Despite his brush with tragedy, Rioseco said he would join the flotilla again. “This was not a foolish thing. We want people to remember those killed by Castro. We are one country, one people, and we want to go back to a free Cuba.”