Something so simple—a large dog towing a swimmer through the water—can have such a profound effect.

With a quarter century of experience as a paramedic in the United Kingdom, Pete Lewin understands how trauma and stress can effect people. That knowledge, coupled with his own traumatic experience, led Lewin to find a unique way to reach out to people and help them deal with their inner strife: Newfoundlands.

In 1981, while on a trip to South Africa, Lewin nearly drowned while swimming out to a boat that was just a short distance from the shore. It was an event that affected him deeply, and Lewin wouldn't swim again for another 15 years until his first Newfoundland—Gruff—restored his confidence in open water.

Belying their massive size, easygoing demeanor, and thick double coats, Newfoundlands are incredibly strong swimmers. Equipped with webbed feet that help them paddle through water with ease, they're powerful enough to pull large loads behind them as they make their way to shore. It was this innate ability that first got Lewin thinking about how his Newfoundlands could help people.

"I'm not a counselor, I'm not a therapist," Lewin tells Daily Paws. "But what I am is a paramedic that listens, and I fully understand what they're going through."

The water therapy Lewin and his current stable of Newfoundlands—Storm, Sonar, Walker, Bob, and Ralph—practice is deceptively simple: Lewin has clients don wetsuits then swims with them a few meters offshore. Once there, he instructs clients to relax and float on their backs until one of the dogs swims out to them. Then, the person will hold on to a handle at the top of the Newfoundland's harness and allow the dog to gently pull them to shore.

"All he does is swim back," Lewin says. "Nobody's calling him, nobody's shouting. He just takes them back to shore."

And once dog and human make it out of the water, Lewin says the calming, restorative effects are easy to see in people suffering from mental health challenges like PTSD.

"When they come out of the water with that big grin on their face because they've swam with the Newfies, it's very, very special," he says.

Lewin, who's been a paramedic with the East Midlands Ambulance Service for 25 years, originally planned for his pups to serve as water rescue dogs. But that didn't work out, so he was trying to figure out how else to employ his dogs while chatting with a colleague.

She told him that a couple years before, she'd been thinking of endangering her own life—but she decided not to because she was scheduled to help Lewin and his dogs at an event. When she entered the water with the dogs, the huge weight lifted off her shoulders, Lewin says.

One of his dogs at the time, Boris, swam to her and looked at her, his gaze free of judgement.

"That was very special," Lewin says.

He said recently he knows of four people who "are still alive today because of what we do."

"Although we developed [the training] for real rescues, we now use it as emotional support because we've got this lovely hold on this person," he says. "They may be in a bad place ... and not feel wanted all the time. And this hold gives them that security that we've got them, and we're looking after them and we take them back to shore."

Over the years, Lewin has plied his trade with a dozen different Newfoundlands, with two more dogs currently in training to join his present stable of five. He loves the gentle giants for their laid-back nature and the calming effects they can have on people who are dealing with extreme stress and trauma.

"It means a lot to me, a lot to the team, and a lot to the dogs," he says of the results of his program. "[The Newfoundlands are] special and I love them to bits. They're so good for everybody else and not just me."