IAC chief and Gotham philanthropist Barry Diller knows things that float will rise to the surface. Six weeks ago, Diller startled New York officials by pulling the plug on Pier 55, his futuristic park and performing arts complex that was going to rise in the Hudson River as a centerpiece in public reclamation of the once-crumbling and abandoned West Side waterfront. Today it appears to be revived.

Known informally as Diller Island, the cost of the project had ballooned from $130 million to $250 million, with no end in sight. In addition, Diller, whose artistic partners on the project include producer Scott Rudin and writer-director George C. Wolfe, had been challenged by several civic groups, some of them financed by a rival, real estate mogul Douglas Durst. In mid-September, Diller announced that he was pulling out of the project, effectively killing it.

What followed was much chest-thumping over the loss. In an editorial, The New York Times called the death of Diller Island  “a shame” and blamed New Yorkers for their “assumption that something untoward is afoot,” whenever private philanthropy endows public spaces. But the project had been moving forward mostly out of the public eye, and some of the challenges – especially those concerning environmental impact and questioning the need for another performing arts complex – were legitimate subjects for examination and debate.

Like Plato’s lost continent of Atlantis, Diller Island now appears to be rising. Urged by New York Governor Andrew Cuomo to reconsider, Diller is back on board. Cuomo got the nit-pickers to agree to end their challenges, he announced Wednesday, while also committing the state to complete the 4.5-mile-long Hudson River Park in which Diller Island will sit, as well as to protect the marine estuary from development.

“I’m going to make one last attempt to revive plans to build the park,” Diller said in announcing the deal, which was first reported by The Times, “so that the intended beneficiaries of our endeavor can fall in love with Pier 55 in the way all of us have.”