Forget the octagon or the ring — Ronda Rousey is looking to go toe-to-toe with sharks.

The Olympian and UFC Hall of Famer participated in a special titled “Ronda Rousey Uncaged” on Sunday where she embarked on shark diving and fed the deep sea’s most terrifying creatures. The show aired on the first night of Discovery Channel’s annual Shark Week.

The 31-year-old was guided by former Navy diver Paul de Gelder, who coached “the baddest woman on the planet” through three rounds of survival training against the heavyweights of the sea.

The training led to the main event where Rousey attempted to step outside the protective cage to face one of the ocean's most ultimate predators — the mako shark.

And de Gelder knows plenty about going face-to-face with a fearsome opponent. In 2009, he was attacked by a nine-foot bull shark in Sydney Harbor while working as an Australian Navy diver. He lost his right hand and most of his right leg.

“My case was just mistaken identity,” de Gelder told Fox News. “I was wearing a black wetsuit with a pair of black flippers. I was swimming on the surface flopping around in murky water and there was overcast. The shark just thought I was a wounded seal, an easy target. So he grabbed me by the hand and the hamstring… Pretty tough day at work I gotta say.”

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Ronda Rousey's shark diving trainer, Paul de Gelder, survived an attack in 2009. (Discovery)

While de Gelder was worried his past experience would spook Rousey, she wasn’t fazed by the warning. Instead, she was all too eager to meet her match.

“This woman had never dived in her life up until we came along,” said de Gelder. “So we had to teach her in a very limited amount of time to go from not scuba diving to knowing and being confident as a diver to almost straight away dive into 17-meters deep surrounded by sharks and then hand-feeding one.

"She could have very easily lost a hand or an arm. That was a very, very real moment for me. Especially because her 6’7” husband was right behind me and probably would have drowned me.”

Rousey and de Gelder dived in Fiji, one of the few places in the world where up to eight different species of sharks can be easily spotted. They also traveled to New Zealand in search of the blue shark, as well as the mako shark. But Rousey’s cockiness as a fighter nearly got the best of her.

“We really did try to take baby steps with her,” said de Gelder. “But… she just wanted to keep pushing… all the way to the point where sometimes we had to pull her back because… the fact that I was actually missing two limbs from a shark that she was about to hand feed just disappeared. And all she saw was the challenge and the excitement. So we did have to pull her back from actually being overconfident once or twice.”

And it wasn’t just de Gelder who kept a close eye on Rousey. Her husband, fellow fighter Travis Browne was also present during filming. De Gelder admitted he witnessed a new, unexpected side to Rousey.

“I think everyone thinks she’s this super badass,” said de Gelder. “And she is. But what surprised me the most was seeing her and her husband together.

"They’re like two little puppy dogs in love, like jumping all over each other, snuggling, kissing, whispering sweet nothings to each other. It was kind of adorable, I gotta say. [And] he literally threatened us with death. There was no mistaking it. He said to us, ‘If my wife doesn’t come back on the boat, ain’t none of y’all coming back on the boat.’”

Browne’s warning was more than enough motivation for de Gelder to ensure nothing went wrong when diving for sharks. He said mistakes can easily happen even after laborious training.

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Ronda Rousey with her shark diving trainer Paul de Gelder. "Ronda Rousey Uncaged" will kick off Discovery's annual Shark Week. (Eric Williams/Discovery Channel)

“It’s hard to see… with all the fish [around you],” he explained. “At some stages, when you’re holding that fish head, waiting to stick your arm out into the open space and feed a bull shark, there are so many fish attacking that head that you actually can’t see through the cloud and [know] when the bull shark will approach you.

"So it can be super nerve-wracking… This isn’t a game. This is serious business… It’s a testament to the audacity, the mental strength and courage that Ronda Rousey has. I think the world is going to see another side to this woman that they’ve never seen before.”

De Gelder said it wasn’t his intention to use his training to make Rousey a fearless fighter when on land.

“My goal was to take this woman, who has never done this before… and show her a different angle on the sharks she has seen in the media,” he said. “They’re portrayed as vicious, man-eating monsters. I wanted to take her on a journey in hopes that she and her millions of followers will fall in love with them as much as I do and want to protect them. And respect them instead of fear them.

“… We are wiping them out. If we look inside the oceans and see what the human impact is doing there, there would be laws and better regulations to save the ocean… People have a fear of sharks because no one wants to be eaten alive. So whenever there is an attack, it’s publicized worldwide… We need to be saving and conserving as many of these animals as we can because they play a vital role in the building blocks of our healthy oceans.”

But Rousey didn’t need much convincing. Not only did she loved the experience, but she’s hoping to eventually step out of the protective cage and get up close and personal with a great white

And as for de Gelder, he wouldn’t change what happened to him. He said the experience has only inspired him to travel throughout the world and serve as a speaker where he encourages others to overcome their adversities.

“It’s the little things that make life worth living,” said de Gelder. “It was a really s---- day at work, but it’s opened up this whole new world for me that I would have otherwise not experienced.”