It was from a hospital bed, in a daze from painkillers, overwhelming media attention and a lingering frisson from her brush with death, that Anika Craney saw the Facebook message:

“Welcome to Bite Club.”

Days earlier, she had been free-diving in the Great Barrier Reef when she saw a shark barreling toward her. She flipped around to put her fins between herself and the predator, but the murky water around her quickly turned crimson.

Blood coursing out of her left foot, she struggled to get to the beach, trying to stem the arterial bleeding and screaming for help. An off-duty medic fashioned a tourniquet out of a belt, saving her life and her limb.

Even in those early moments, Ms. Craney, then 29, was determined not to let the experience affect her lifelong bond with the ocean. From a gurney, as she was taken from the rescue helicopter into the hospital, she cried out to a swarm of news cameras: “I still love sharks!”

What she didn’t know was that the bite was the beginning of a long journey.

Yet to come were searing nerve pain, nightmares, sleepless nights, hallucinations and the loneliness of suffering from physical and psychological wounds that few can relate to. Still ahead were the offers of quick money for an interview or a documentary, which would only renew her trauma and underscore that the world’s interest was in the gruesome details of her encounter, not the grueling recovery that would never truly be over.

But Dave Pearson knew — because he had been through it a decade earlier, after a shark shredded his left forearm down to the bone, profoundly altering his life and his mind.

So he reached out to Ms. Craney, as he has for many other survivors in the years since his own bite, welcoming her into a fellowship no one would want to join. Over the phone, in his calm, steady voice, he told her a bit about what to expect, and he said there was a group of people she could turn to.

“We’ve been through this and we’re here for you, through every step of the way,” she later recalled him saying.

‘Why Me?’

There is a pattern, Mr. Pearson has learned, to what comes after the bite.

There is the elation of survival, the celebration of a miraculous escape, the inundation of attention. Then, often, comes months of obsession, spent researching everything about the creature and its behavior.

“You just want to know, why me? What did I do wrong?” he said. “The hardest thing to accept is you did nothing, you were just in the wrong place at the wrong time.”

Mr. Pearson, 62, is the founder of Bite Club, a network of shark attack survivors (plus family members, first responders and a few people who’ve been bitten by other animals, like crocodiles). It started in Australia but now has more than 500 members across the world. Its private Facebook page functions as a medical forum, a middle-of-the-night lifeline, a post-traumatic stress disorder support group and an accidental family.

It is an exclusive club, one with many members in Australia, where the vast majority of the population lives near the coast (the country regularly reports more human-shark encounters than any other, except for the United States). Last year, 47 “unprovoked” shark bites were reported worldwide, four of them fatal.

Mr. Pearson, an affable Everyman with the sunbaked hue of a lifelong surfer, joined those rarefied ranks in 2011.

During an afternoon surf at his local beach at Crowdy Head, a few hours up the coast from Sydney, a bull shark sank its teeth into his brand-new surfboard — and his left arm, including the wrist and the hand. His buddies pulled him out of the water and tried to slow the catastrophic bleeding with a tourniquet, using his surfboard leash.

Lying on a beachside picnic table, he cracked jokes and admired the sunset while waiting for a helicopter to arrive, thinking it was not such a bad day to die. When he emerged from surgery, he was ecstatic to see that his arm had not been amputated.

Once the blur of the first weeks was over, though, a quiet new reality set in. There were long days alone, addled by painkillers, and fraught nights during which scenes from the fateful day replayed in his dreams. He could not turn to the one place where he’d always sought solace: the ocean.

“The shark decided to upturn that basket where I’ve been hiding everything my whole life,” he said. “I thought I was doing really well, until I wasn’t.”

During his time in the hospital, he met a young woman about his daughter’s age, who had been bitten a week before he was. He was amazed at the instant connection they felt.

Mr. Pearson began reaching out to every shark attack survivor he could get in touch with — calling hospitals, asking journalists to put him in touch, talking to local government officials who worked on shark safety. He started calling survivors regularly on his commute, sometimes driving for hours to meet them in person.

When he realized there was no place where they could share their experiences and exchange information and advice, he thought: “Let’s become that group that just supports people.”

His first idea for a name, Australian Shark Attack Survivors and Friends, was a mouthful. “Bite Club” came up as a joke in a late-night conversation over beers and wine. It was snappier.

Someone to Talk to

Most discussions of human-shark encounters are accompanied by the caveat that they are exceedingly rare. People are more likely to be killed by bee stings or lightning strikes, and getting bitten by another human is far more common.

But there’s a flip side to that: If you do have a run-in with a shark, very few people know what you’re going through.

Ms. Craney is a lifelong swimmer and diver who, as a child, doodled dolphins in every textbook and daydreamed about becoming a mermaid. She was living on a boat off Australia’s eastern coast, working on a film crew for a series about the Coral Sea, when a quick swim with a colleague to look for sea turtles ended with the bite.

Not long after speaking with Mr. Pearson on the phone, she introduced herself on the Bite Club Facebook page.

“Hi, my name’s Anika and I was just bitten by a bull shark in Far North Queensland,” she recalled writing. “I was bitten on the left leg, and I’ve got this damage, deep and superficial peroneal nerve damage, three tendons severed, dented tibia bone and a tooth shattered in my bone.”

Her nerve pain was harrowing — “It feels like you’re being electrocuted, or like you’ve got red ants biting you all over your skin” — but psychologically, she thought she was one of the lucky ones. Many survivors never go back into the ocean; some can’t even bear to face it, sitting at the beach with their backs turned to the water.

But within a couple of months, Ms. Craney was back in, swimming and diving. She went to work as a skipper for a boat charter company.

A little more than a year after her attack, while surfing with Mr. Pearson and his partner, Debbie Minett, she dove under a wave and saw, crystal clear, a shark with its mouth agape, hurtling toward her.

“I blinked, and it disappeared,” she said. It had been a hallucination, vividly imprinted into her brain.

“I burst into tears and called out for them,” she said. “I said, ‘I need to get out, I need to get out.’”

At work, she began hearing phantom cries for help, or people yelling, “Shark!” She had to give up the job. At night, the image of the approaching shark would play on a loop in her mind.

On those nights, she would turn to the Bite Club page to see if anyone was awake, someone she could talk to. There always was.

“The mental hurt becomes louder when you feel alone, but when you can relate to other people, you don’t,” she said. “It’s honestly lifesaving.”

An Affinity, an Understanding

Earlier this year, at the tail end of Australia’s summer, Mr. Pearson went to Bondi Beach in Sydney to meet with Andrew Phipps Newman, who was bitten by a shark in the Galápagos Islands in 2018.

Bondi’s pristine sand and water were brimming with sunbathers, swimmers and surfers. Mr. Phipps Newman found himself constantly scanning the waters for dark shadows.

He was in Sydney on a business trip from Britain, and Mr. Pearson and Ms. Minett had driven four hours south to see him. It was the first time the men had met in person, but they immediately embraced in a bear hug. Another Bite Club member, a young woman who was attacked last year, briefly stopped by to say hello. “You’re both leg people,” Mr. Pearson told them.

“You just have an affinity. There’s a warmth, there’s an understanding,” said Mr. Phipps Newman, who had met only one other survivor in person before, back home in Britain, through Bite Club.

Mr. Phipps Newman had been reeling from his husband’s unexpected death when he joined the Galápagos snorkeling excursion on which he was bitten. When he felt the powerful force pulling him down, he thought a fellow tourist was playing a joke. Instinctively, he punched the shark in the nose twice, and it let him go.

In that moment, he said, for the first time in months of wallowing in grief, he felt a strong will to live.

He had stayed away from the ocean in the seven years since then. On this day, though, at Mr. Pearson’s urging, Mr. Phipps Newman took his socks off and waded briefly into the water, up to his shins. Bite Club members often accompany one another for their first return to the ocean, or for a swim or a surf to mark the anniversary of their attack.

Mr. Pearson has a nearly encyclopedic knowledge of club members’ injuries, and he connects people who he thinks will benefit from speaking with each other, almost like a sponsor in a recovery group. He put Ms. Craney’s father in touch with an American whose daughter had also been attacked. The two men, both of whom joined Bite Club, had suffered from nightmares, fear of the ocean and a paralyzing dread for their daughters.

A few club members are people who lost relatives to shark encounters — reminders, to the others, of how easily their stories could have ended differently.

Some of those members have asked survivors about the pain they suffered, wanting to know what their loved ones’ final moments were like, Mr. Pearson said. He assured them that in the first 20 minutes of the experience, with adrenaline coursing through his body, he felt absolutely nothing.

Back in the Water

Last month, Ms. Craney marked the fifth anniversary of her attack. She is back in the water, swimming and diving. She recently moved from Sydney back to Cairns, near the site of her bite, to be closer to the ocean she loves. She is also starting a business, teaching diving to people who struggle with trauma.

On her drive up, she stayed with Mr. Pearson and Ms. Minett at their home in Coopernook. They went for a quick swim at Crowdy Head, where Mr. Pearson was attacked, near where she hallucinated. She peeled off socks that featured cartoon sharks and, on the soles, the words “BITE ME.”

Looking out at the waves he’s surfed for five decades, Mr. Pearson said that his attack, more than 14 years later, still colored his every encounter with the ocean.

“I used to stare at the waves, thinking of how I would ride each one,” he said. Now, each surf is tinged with fear. But he swallows it and paddles out, several days a week.

How long does an attack stay with you? A few years ago, Mr. Pearson got a call from a staff member at a nursing home, who asked if he would meet with a resident in his 80s. The man, who had Alzheimer’s, was experiencing night terrors that seemed to stem from his experience with a shark. The man had been attacked in 1955.

Mr. Pearson visited him twice, listening to his story, as he does for new members of Bite Club. Even though the man couldn’t remember Mr. Pearson’s name on the second visit, he recounted the details of his attack as if it had just happened.

Their chats seemed to bring the man peace, and his nights were calmer after that. For Mr. Pearson, that’s what it’s all about. What he has lost in his uncomplicated love for the ocean, he has gained in profound connections with hundreds of people around the world.

“You get to make a difference,” he said. “We share this thing.”