While the Air Force has done other projects with private companies before, this is the first time it has ever merged a base with a hotel, said Mike Spaits, the base spokesman.
The dome was added to the radar installation to make it "less military and more visitor-friendly," said Wesley Mason, a contractor who helped develop the project.
Outside, tourists with drinks in hand floated through the landscaped, beach-front pool featuring a rocky waterfall fountain. Inside, families browsed the beach-themed gift shop and dined at a restaurant overlooking the pool.
The military presence is unobtrusive and limited to a few people, often contract employees without uniforms, who work on the roof.
Lamon Moody, a hotel guest from Baton Rouge, Louisiana, relaxed on the beach with his family on a recent afternoon. Moody said he had no idea the beach ball covered military equipment.
"I think that's pretty cool. I'm in favor of anything that helps out the military," he said.
Another vacationer, Jeff Harwell of Fort Worth, Texas, said he and his family had speculated about the giant beach ball.
"We talked about it when we were first noticed it," he said. "We thought maybe those things sticking out of it were lightning rods."
The hotel was a win for both sides. It allowed the military to make use of small section of beachfront it owns on Okaloosa Island that is cut off by commercial developments from the rest of the Eglin's more than 17-mile expanse of beach, Spaits said. The military couldn't make good use of the land for beach training exercises or test missions without building a tower or other structure to place equipment above the surrounding hotels, restaurants and shopping centers. Innisfree is paying the military about $190,000 a year in rent, the Air Force said.
It allowed the hotel company to build on a prime beachfront site surrounded by popular attractions such as the Gulfarium marine park and the nearby convention center, said Ivana Coteat, the hotel's sales director.
"This is a perfect location. You can see us right from the bridge on Highway 98. You cannot miss us," she said.
People from the area who know about the arrangement occasionally ask for a tour of the roof, but it is off-limits, Coteat said.
Chris Nixon, who oversees testing at the range, said Test Site A5 is a coveted posting for workers who monitor testing and equipment because of its view overlooking the pool and the beach.
"It is a popular place to work," he said with a laugh.
The roof also features a small conference room where military officials, including Brig. Gen. David Harris, commander of Eglin's 96th Test Wing, can hold classified conversations.
But Harris said the most important benefit of the partnership is the morale boost it provides military families who get discounted rates at the resort.