DESTIN — When the phone rang, Navy Lt. Kenneth Van Belkum was home with his wife.

He was gearing up to get his detachment of Seabees to Bermuda, where they were slated to build a base exchange and some recreational facilities.

Yet the caller said Van Belkum and his detachment weren't going to Bermuda anymore. Instead, they'd be heading out from their Rhode Island base to Swan Island, a dot of land off the coast of Honduras. Coming along would be enough materiel to build housing for 50 people and carve a runway.

And, mysteriously, they'd also be erecting an antenna.

"The antenna was provided by ... whoever," Van Belkum recalled of the cloak-and-dagger nature of the assignment.

What Van Belkum didn't know then — and wouldn't know for years — was that he and his Seabees were helping to set the stage for what turned out to be the disastrous Bay of Pigs invasion of Cuba.

The invasion came 58 years ago this week in 1961, a little more than two years after communist Fidel Castro and his guerilla army seized control of Cuba from Gen. Fulgencio Batista, the island nation's American-backed president. Nearly 1,500 American-trained Cubans who had fled the island when Castro took power staged the CIA-backed invasion, but badly outnumbered, they surrendered within 24 hours.

Van Belkum's role began more than a year earlier on March 17, 1960, as President Dwight Eisenhower approved a plan to aim propaganda at Cuba, including construction of a radio station, as part of an effort to topple Castro's regime. The job was assigned to the CIA, with a 60-day deadline.

With a top-secret classification, things happened quickly. By evening on the Sunday that Van Belkum had received the phone call and sketched out a plan, all of the immediately needed materiel was on the Rhode Island dock waiting to be loaded for Swan Island.

"I'd never seen the Navy supply system work like that," Van Belkum said as he sat in his sun-splashed Destin home earlier this week amid an array of photographs — some his own, some carrying a "Confidential" marking — from the mission.

Once on Swan Island, Van Belkum and his men erected 10 Quonset huts, dug water wells, built a water tower, got electrical generators up and running and laid a 3,000-foot runway.

"It was fun, the work we were doing," he said.

When they weren't working, Van Belkum and his men enjoyed snorkeling in the crystal-clear water. And on occasion, Van Belkum admitted, boats running Cuban rum across the water would stop by the island.

Still, it was a bit unsettling to have civilians, widely suspected to be CIA personnel, working mysteriously alongside them.

"What these guys were doing, I had no idea," Van Belkum said. "Oh, we all guessed about it. We kind of surmised that things were going on that we didn't know."

One day, a mysterious room-sized box was delivered. Van Belkum was asked to set it next to the antenna. The "box" was the transmitter for Radio Swan, which went on the air May 17, 1960 — the exact deadline set by Eisenhower.

Hints of the importance of getting Radio Swan on the air, and the secrecy of the project, are contained in a commendation letter to Van Belkum from Adm. Arleigh Burke, then-chief of U.S. naval operations. The letter was placed in Van Belkum's personnel file within weeks of the Seabees leaving Swan Island, but it was classified and Van Belkum didn't learn of its existence for years.

Even today, Van Belkum marvels at the correspondence.

"Lieutenants never get a letter of commendation from the Navy chief of staff," he said.

Still, the letter provides no hint of what happened on Swan Island. Burke called the assignment only "a very urgent project of great importance to the United States." The letter concludes by noting that the "physical results and timely completion which were Lieutenant Van Belkum's immediate responsibility reflect great credit upon the Navy and himself."

The ultimate results of the project were mixed, according to a study led by then-retired Army Gen. Maxwell Taylor and compiled as the Taylor Commission Report, a post-mortem on the Bay of Pigs invasion.

According to the report, Radio Swan was supposed to be a clandestine station, but was made a commercial station because the Navy had "reasonably argued that should their participation in construction of a black facility be known, explanations would be difficult."

As a result, the widely heard Radio Swan carried paid programming from various Cuban exile groups. Castro tried to jam the signal, but succeeded only in Havana. A month before the invasion, the CIA halted the paid political programming, switched to all-news format that included occasional coded messages to resistance forces that continued through the invasion. The station stayed on the air until 1968, when its transmitter was shipped to Vietnam.

In the ensuing years, Van Belkum heard "different little stories" about the work on Swan Island. He unearthed little information about it, though, until learning of the Taylor Commission Report.

"It took me 50 years to find out it was Eisenhower," he said.

Van Belkum retired from the Navy in 1975 before going on to a private-sector career designing airports. Still, he marvels at the circumstances that placed him in an important side note to American history.

"I was just sitting there at home, waiting to go to Bermuda," he said.