On sun-drenched days in 2022, the cryptocurrency entrepreneur Brock Pierce liked to take his friends sailing to the island of Vieques, about 75 miles from his home in Puerto Rico. Mr. Pierce wanted to show off a property that he described as “the most important passion in my life”: a once-glamorous beachside resort that he had recently bought for more than $15 million.

In its heyday, the resort, a W Hotel, boasted a 6,000-square-foot spa, restaurants run by a Michelin-starred chef and sweeping views of the ocean; it was a key source of tourism jobs in Vieques. Then, in 2017, the hotel was damaged by Hurricane Maria, forcing it to close. Mr. Pierce planned to reopen it, using his crypto riches to revitalize both the glistening property and the local economy.

A former child actor, Mr. Pierce knew how to put on a show. On the trips to Vieques, he would anchor his Italian-made yacht at a local harbor, then lead his guests to the gates of the shuttered W, along a stretch of beach where wild horses roamed.

“This was my massive personal bet,” Mr. Pierce said recently. “This was where my heart was.”

But Mr. Pierce’s display of opulence was something of an illusion. Like many other grandiose projects that he has started in Puerto Rico, the hotel’s revival is now mired in unpaid bills and legal quarrels. Last fall, Mr. Pierce lost the W in a dispute with another investor. The hotel is still closed, its windows smashed and its floors covered in mold and horse dung. A $17,000 lounge chair, designed by a prominent Spanish architect, is collecting dust in the empty atrium.