Doing a good deed nearly cost Ruth Coules her life.

Coules, 56, has for the past two years collected fishing lines and hooks from the ocean at Lanikai Beach to prevent marine life entanglement and damage to the reef.

While swimming this summer, she saw a monofilament fishing line stretched between two rocks underwater. She dove down about 10 feet, as she had many times before, pulled gently on the line with her bare hand, and felt a sharp pain. She was underwater with a fishhook embedded in her ring finger. From experience, she knew there were some lines that were easy to break, and some, slightly thicker, that were not.

Her life, she said, flashed before her in those few seconds. Her last thought was: “This is the one I can’t break.”

Then somehow, by a stroke of divine intervention or adrenaline, she managed to surface and swim to shore. At the emergency room, doctors extricated a barbed hook from her finger.

Ten days later, the Lanikai resident was back in the ocean, doing what she always does.

“This is really personal to me,” Coules said. “This is my kuleana. The ocean saved me and this really teeny, tiny thing that I’m doing is the least I can do while out in the ocean.”

Coules, co-owner of events management company Coul Productions, has always loved the ocean. She visited her grandparents every summer in Hawaii while growing up in southern California. When she moved to Lanikai with her family three years ago, she would get into the ocean almost every day to do stand-up paddling.

Then on Valentine’s Day last year, she felt a strange numbness in one leg and then the other. The mother of three was diagnosed with a spinal cord condition that resulted in limited sensation to her legs and feet. She had to learn how to walk again. She could no longer do stand-up paddling, but she could swim, and the ocean became her sanctuary.

“It was a place where I felt myself again and I was normal,” she said. “I feel like it saved me.”

A long-distance swimmer, she spent hours looking down at the ocean floor and began to notice how fishing lines were wrapped around coral heads. The day she saw a turtle with its fin wrapped in fishing line, it broke her heart.

So every morning, she swims with her snorkeling gear, a mesh net, clippers and pliers, removing lines and other debris while underwater.

After the fishhook incident, she no longer reaches down to grab anything by hand, using tools instead. One is a special cutting tool at the end of a stick fashioned for her by her father.

Mary Wallace, also a Lanikai resident, met Coules at the beach, watching over a turtle snagged by fishing line a few weeks ago, and nominated her for Heroes Next Door after learning of her mission.

“Her example of contributing her time and energy for the good of all of us without any need for recognition is selfless service, the purest kind,” Wallace told the Honolulu Star-Advertiser. “I recognize her as a quiet hero that sets an example for all of us.”

Recently, Coules also began to pick up the tiny pieces of plastic debris from the fine sand on the beach, using sifters she made out of mesh from the hardware store. Just like with the fishing lines underwater, she began to notice them on her way to the ocean.

Coules has a personal motto: “I know I can’t do everything, but it doesn’t mean I can’t do nothing.”

We recently asked readers to help shine a light on the good works of a few true unsung heroes. Readers responded with nominees from divergent walks of island life who share a common desire to help others. Star-Advertiser editors chose five Heroes Next Door who have been highlighted in stories this week.