"I was so, so happy!” exclaimed Sara Campbell. She's the real-life mermaid who set a new world record diving an incredible 316 feet straight down into the ocean.

Describing the fishlike feat, Campbell says, “It's a great feeling. It's total freedom."

For the 37-year-old, it all started with one giant breath. Then her incredible journey began. The 5-foot-tall powerhouse pumps her legs like a mermaid, out-diving most of the men in the world. She swam so deep she actually disappeared into the murky depths off the coast of the Bahamas.

"At 40 meters below the surface, I couldn't see my hand in front of me. It was pitch, pitch black," she says.

When asked if she ever felt like she just couldn’t make it, Campbell explains. “On the dive itself, no. But in the training period running up to it, yes. Many, many, many times."

At the bottom, Campbell picked up a tag to prove she was there and brings it with her to the surface.

She stayed underwater without scuba gear for a remarkable 3 minutes and 35 seconds before resurfacing and taking a much-needed breath. Initially there was a tense, very quiet moment. If Campbell blacked out, she'd be disqualified. Finally, when it's clear she's okay, the crowd erupted in exaltation.

What the world didn't see was what happened to Campbell not long after she set the new record. She risked everything in a second dive to go even deeper, hoping to become the first woman ever to freedive 100 meters (328 feet).

"I made it to the bottom. I made it back to the surface, took two breaths but the pressure change in the last 10 meters coming back to the surface is massive and it was a little too much for my body to cope with and I suffered a very short black out," says the daring diver.

The safety team immediately swung into action, cradling her lifeless body.

However, Campbell is not letting that setback scare her. She's already back in training to break her own world record and dive even deeper. “I do it because I absolutely love it and there's no other reason."