Aquarius has served scientists, researchers, underwater filmmakers and Navy divers. Forty NASA astronauts also have trained in the habitat before going to space.

The yellow, 81-ton pressurize tube has six bunks, a bathroom, galley, science station, state-of-the-art communications and “wet porch,” from which aquanauts can enter and exit.

The habitat’s best asset is its ability to give aquanauts the “gift of time.” They can work for long hours in the ocean without worrying about having to surface for air. The habitat also provides an “alien atmosphere” that simulates a space station and the zero gravity of asteroids.

Earlier this month, Earle and Patterson led Aquarius’ 117th — and possibly last — mission. For seven days, six aquanauts lived and worked at 60 feet below the surface at thriving Conch Reef. They conducted three science projects, while celebrating the 50th anniversary of human habitation on the sea floor.

But the mission primarily was a public relations crusade to save Aquarius from being mothballed.

Underwater filmmaker DJ Roller, one of the mission’s aquanauts, provided free streamed footage of the mission. Nearly 250,000 people watched.

“We made a cool discovery,” Patterson said. The aquanauts learned that Goliath groupers disable their prey by blasting them with sound created by cavitation bubbles, which are caused by extreme pressure drops in their mouths.

“When the bubble collapses it makes an incredible shockwave,” Patterson said. “You hear a low base click and hear a thump going through your chest like somebody punched you in the gut.”

Patterson said this discovery likely will become published after peer review. More than 300 scientific papers stemming from work at Aquarius already have been published in major science journals. He said there is so much more to learn, including potential medical breakthroughs. “Locked away in the body of sponges could be the complex compounds that have the cure for cancer,” he said.

Thomas Potts, director of the Aquarius Reef Base Program, said now is not the time to end this last-of-its kind program.

“We should be triple or quadrupling what we are doing,” he said. “We’re just starting to touch the surface of learning about ocean acidification and global climate change on the reefs. We finally have the technology that allows us to develop censors to take a good look in the water column and see what’s happening at the bottom.”

Potts works for the University of North Carolina-Wilmington, which has been operating the program for years with grant money from NOAA. The university will end its affiliation Dec. 31, when the current budget ends. There already is a for sale sign outside the rented house in Key Largo that the program has been using as its land headquarters. Its staff of 17 has been reduced to about five.

Aquarius has faced dire times before. Its original home was in the U.S. Virgin Islands, until Hurricane Hugo destroyed St. Croix in 1989. That led to relocation in Key Largo. During two budget years the program received “zero funding” but got a reprieve. This time, however, was the first time the budget called for the program’s “termination.”

Aquarius employees say they were blindsided with the news in February. Since then, with seed money from the Florida Keys National Marine Sanctuary Foundation, the nonprofit Aquarius Foundation was formed to try to raise private money to keep the program afloat.