UFC star Donald Cerrone is known for his exciting style inside the Octagon and his death-defying stunts outside of it. But his latest extreme sports adventure almost led him to the great beyond.

Appearing on The Joe Rogan Experience on Wednesday, “Cowboy” was asked about a recent cave diving trip, the story of which he initially shared to social media a week ago.

In the post, Cerrone wrote that he was grateful to be alive after experiencing a “catastrophic worst case scenario,” a phrase that only scrapes the surface of his ordeal.

Cerrone, 35, is an experienced cave diver, having earned his certificate in high school, and on this occasion he was in Cozumel with some friends, where they spent a few days hanging around the coral reefs. Later on, he and one other associate decided to go for a more serious dive.

This friend, who Cerrone credits with teaching him a lot about cave diving, was an older man, and Cerrone’s wife Lindsay warned him that she was worried his declining motor skills could put the two of them in danger. Cerrone did his best to assuage her fears.

“I’d just kissed my girl and my new baby. She’s like, ‘I don’t really want you to go. The guy you’re going with, I’m worried.’ I said, ‘What are you worried about? I’m coming home.’ This is what I do, I come home every time, I’m coming home,” Cerrone said. “So I order another cylinder of air, just to f*cking have it. No one’s ever died because they have too much air. In cave diving, you dive in thirds, so if we have 3,000 PSI, we’ll do 1,000 PSI in, we’ll do 1,000 PSI out and we have 1,000 PSI in case something f*cking happens.

“Also, in cave diving you have lines. In a cave, you’ll already have a line run, a bunch of guys like me, tech divers have gone into caves, they discovered them, they mapped them, they named them, and they put lines so you can follow them in case something happens. Get in and get out.”

At some point during the dive, Cerrone’s friend made a mistake while venturing off on his own and found himself in trouble. He began to panic, which is the worst thing anyone can do in that situation — “panic kills everybody,” Cerrone said — and Cerrone was forced to make a decision: Go and help his friend, who at that point was tied up in the line they’d set up, kicking and spinning out of control, or save himself.

Cerrone explained that it’s an unwritten rule among divers that self-preservation is a priority due to how easy it is for the situation to escalate, but he broke that rule and went in to help his friend, putting them both in peril just as Lindsay had thought might happen.

All of the kicking and thrashing about caused a buildup of silt in the water, making it impossible for Cerrone to even tell where his friend was. The man’s light was off and Cerrone didn’t know if he had any air, if he had his regulator, or what condition he was in. At some point, Cerrone lost track of him completely and just like that he found himself alone in the silt.

“As soon as I go into the silt, I f*cking lose everything,” Cerrone said. “Lose my way, where I am, my up, my down, I don’t know where I am. I’m f*cking panicking now. I’m panicking! F*cking freaking out more than I’ve ever, breathing hard, bang, I hit my head on the f*cking ceiling and I just close my eyes and I’m like, ‘Goddammit calm the f*ck down, calm the f*ck down, calm the f*ck down, breathe.’ I can’t even see my hands in front of me.”

Eventually, Cerrone was able to see the lights from his two watches, but still had no concept of what direction he was in or where he was in the cave. He’d taken a compass reading upon entering, so he at least knew the direction he came from, information that did him little good considering the non-linear nature of the underwater structure.

All Cerrone could do was search blindly for the way out, while clinging onto any sensation he could use to determine his progress.

“You’re swimming against the current, so you’re going the wrong way,” Cerrone said. “I somehow worked that into my f*cking panicked mind. ‘We’re swimming into the current, we’re swimming into the current, we’re going the wrong way.’ So I f*cking turn and swim back, I’m back on the f*cking main line again. I find the main line just out into the clear, main line. ‘F*ck, f*ck, f*ck!’ I start hyperventilating and panicking and I’m thinking, ‘You f*cking piece of shit, this is how people die, what the f*ck are you…?’ And I’m keeping in mind kissing my wife and kissing my kid and saying, ‘I’m coming home. I’m coming home.’

“So I do it again, f*cking venture into the f*cking great unknown, f*cking abyss, total blackout. Another panic, another panic, f*cking freaked out, can’t find my way, hitting my head, kicking, losing air by the f*cking second. Because now I’m breathing hard and I’m breathing f*cking irrational and I’m sucking my tanks dry. Mind you, there’s no answer to this after I breathe my last breath.”

Alternating between calm and panic, Cerrone managed to remember how deep he was and also estimated that he had about an hour of air left. Those rare moments of clarity were spent thinking about drowning, which he described as his “biggest fear,” rigging his buoyancy control device to lift him up to the cave ceiling where he could at least search along the surface for an exit, and most disturbingly, wondering how he was going to explain his death to his family.

“When I run out of air, I’m now thinking in my mind, how am I going to die?” Cerrone said. “Tell my wife, tell my kid I’m coming home and now I’ve got to f*cking realize how am I going to die? I have a notepad that you carry in your pocket to draw and write on, I’m thinking, ‘What are you going to say? What’s your letter going to be? You’re writing a f*cking death letter? You’re awake. You’re a fighter. We figure this out. We don’t f*cking find a way to quit, you f*cking bitch.’

“These are the conversations I’m having with myself while I’m in f*cking complete panic mode and complete darkness, thinking that this is how people die. What the f*ck are you doing? You’re going to write a letter to you’re f*cking kid and tell her how you f*cked up, ‘I’m sorry, daddy’s not coming home?’”

After much frustration, Cerrone recalled that there was a huge crack that ran along the top of the cave and, still panicking, he began to search for it. He found it and followed it until he saw light but in one last cruel twist, became stuck on his initial route. However, he abandoned the idea of getting out through that hole and followed the crack along further until he was able to find his way out.

His friend had made it out as well, and he and Cerrone shared the somber realization that this would be the last time they dove together — though Cerrone told Rogan that he still plans to cave dive in the future. Cerrone texted his wife and told her there was “a scary f*cking moment, but daddy’s coming home.”

Cerrone says the experience messed with his head and he still has nightmares about being lost in a dark cloud of silt. Unlike other times in his life where he’s nearly died, this was a torturous, drawn-out experience, where he was constantly aware of how his time was ticking away.

Consciously, the thought of death was unavoidable, but the inner “Cowboy” was as lively as ever.

“The inner me, the fighter: ‘You figure it the f*ck out,’” Cerrone said. “But was I going to write a letter? I was f*cking damn close to writing a letter.”