It's a challenge very few have undertaken: Discovering the mysteries that lie under water. Less than 5 percent of our oceans have been explored.

On Sunday, a team of ocean explorers will dive in, just off Key Largo as part of Mission 31. At the helm, a man for whom adventure runs in the family.



"It's hard to turn your back on the ocean, once you have been immersed in it, because it's such a fantastic world," said Fabien Cousteau, the first grandson of famed underwater explorer Jacques Cousteau.

Like his grandfather, Fabien Cousteau is an ocean explorer and documentary filmmaker. He will pay homage to a mission his grandfather led nearly 50 years ago in the Red Sea. Ocean explorers then spent 30 days living in an underwater village. Now a new generation of aquanauts will do so for 31 days.

"It's freedom, to me its my home," he said.

That home will be the Aquarius, an 81 ton living reef. It is 63 feet below water. The world's only underwater research lab. The space is the size of a school bus, so the crew will be in tight quarters. It includes six bunk beds and a mini-kitchen. It even comes equipped with air-conditioning, but not a whole lot more.

"It won't really set in until you sit down that first night, that galley window and you look outside and see all these fish swimming around. I'm living underwater right now. This is really cool experience," said Florida International University PHD candidate Andrew Shantz.

He has taken part in a shorter mission. That one was 7 days. But opportunity to do what he'll do in June is rare. His team will spend most of its time conducting research on the impact of climate change and the impact pollutants like plastic have on marine life. He'll have very little downtime, and little space to indulge in it.

"I have my headphones to bring down, three books," he said. "Everything else will be work space."

While so much has changed in the time the senior Cousteau led his underwater mission, many things are similar like the way food, electronic equipment and towels are delivered to Aquarius. Divers use pressurized painting pots. One thing Fabien's father did not have is WiFi.

"Being able to do Twitter chats, and Facebook posts and Instagram, to be able to share this experience is something my grandfather was never able to do," Cousteau said.

Their adventures will be streaming live on Mission-31.com. Through Skype in the Classroom sessions, students from across the globe will be able to vicariously join the explorers.

It's a mission that honors a legacy of connecting human beings to the vast unknown under water.

"My grandfather used to say, 'If one person for whatever reason has a chance to lead an extraordinary life, he or she has no right to keep it to themselves,'" Cousteau said.