“Fabien Cousteau is on the ocean floor right now, and he’s not coming up for air until July.” So begins Svati Kirsten Narula’s story in the Atlantic magazine about the undersea adventure called Mission 31.

Fabien Cousteau and fellow aquanauts plan to live in Aquarius, an underwater marine lab, for 31 days. (Carrie Vonderhaar)

Cousteau — grandson of the legendary Jacques — and a small team of fellow aquanauts are living in an underwater habitat called Aquarius and hope to stay there for 31 days. Sitting on stilts about 60 feet beneath the surface a few miles off the Florida Keys, Aquarius is about 9 feet by 43 feet — about the size of a school bus, as Cousteau says. To combat claustrophobia, the crew plans to spend several hours every day doing rocket-pack-assisted swims and tooling along the continental shelf on underwater motorbikes.

Researcher Liz Magee swims underwater during a training session. Mission 31 marks the 50th anniversary of Jacques-Yves Cousteau’s 30-day underwater exploration. (Kip Evans)

Fabien Cousteau sits on the shoulders of his grandfather, Jacques-Yves Cousteau, world famous underwater explorer in the 1970s. (Anne-Marie Cousteau)

Cousteau and two technicians arrived June 1 and plan to remain on Aquarius for the entire 31 days. Two teams of three researchers each will each spend half the time on board, mainly studying the effects of climate change and pollution on the coral reef. Beyond that, they just want to get better acquainted with the vast underwater world that oceanographers including Cousteau believe is woefully underexplored. (As submarine designer Graham Hawkes once scolded the scientific community, “Your rockets are pointed in the wrong g------ direction!”)

To engage a global audience, the underwater team will keep up regular communication with reporters, teachers and students via e-mail and Skype. And the entire adventure is being broadcast live online at the Mission 31 Web site.

When we tuned in the other day, the interior of Aquarius was pretty mundane, with T-shirt-clad researchers sweeping something off the floor (there’s no sound, so we didn’t know what), checking their dials, squeezing quietly past each other in the narrow control space. But the action outside was lively, with dozens of brilliantly colored fish poking attentively at the 80-ton behemoth that had suddenly appeared in their world. Curiosity, it seems, works both ways.