Riding in a boat carrying 48 people about to swim from Alcatraz Island to San Francisco’s shore, 14-year-old Ari Hirson turned to Rabbi Ryan Bauer of Congregation Emanu-El.

“This is a Shehechiyanu moment,” Ari said to his fellow participant, acknowledging that he was about to take on the toughest swimming challenge of his life.

During his childhood, Ari had watched his family members make the roughly two-hour, 1.5-mile swim — and now it was his chance to do it with them. On top of that, Ari and his 17-year-old brother, Noah, had spent the better part of a year planning the event, a fundraiser their parents started in 2011 called Alcatraz Swim for Sight.

Ari and Noah’s 52-year-old mother, Lorie Hirson, has been slowly losing her vision since she was diagnosed with retinitis pigmentosa at age 18. It’s a rare, hereditary eye disease that causes cells in the retina to slowly break down over time.

Of the more than 80 genetic mutations that cause RP, Lorie’s mutation is linked to one prevalent among Ashkenazi Jews. Her oldest brother has it, too. Although Ari and Noah are genetic carriers, neither of them will develop the disease because their dad, Ron Hirson, is not a carrier of the mutation.

Over the last three decades, Lorie has lost her peripheral vision and is now classified as legally blind. “It’s completely tunneled,” she said of her current field of vision. “It’s like looking through a paper towel roll.”

In a joint Zoom interview with Ari and his mom from their home in San Rafael, Lorie told  J. about her condition. “Every three to five years, I’ve had to readjust to my new world,” she said.

For instance, when Ari was born, she stopped driving out of concern for how her worsening vision could impact her children’s safety. As the disease nears the end stages, she said, her eyesight is projected to deteriorate at a slower pace. “Eventually it will be a pinpoint,” she said. “The goal is that hopefully that pinpoint of light or shades won’t disappear completely.”

For Lorie’s 40th birthday in 2011, she and Ron started Alcatraz Swim for Sight, which raises money for medical research focused on saving and restoring sight.

This year’s swim, which took place on Sept. 17, was the eighth one and raised $147,600. Each adult swimmer paid a $150 entry fee and was urged to donate or raise an additional $2,000; student swimmers paid $75 each and were encouraged to raise an additional $500.

To date, Alcatraz Swim for Sight has raised about $1.15 million for the All May See Foundation, a national nonprofit dedicated to curing and preventing blindness, serious eye diseases and visual impairment. It’s the fundraising arm of the UCSF Ophthalmology Department. According to the Hirsons, 100% of donations to Alcatraz Swim for Sight support research at UCSF.

Lorie, who serves on the All May See board, was a competitive swimmer for her high school and on a club team until her diagnosis, and Ron played water polo in high school and college — which is how they came upon the idea of staging a fundraiser in the cold, open waters of San Francisco Bay. Early in their courtship, Ron swam in a local competition from Alcatraz to San Francisco.

“I saw him come in and it was so inspiring,” Lorie recalled. “I was like, ‘I could do that.’”

She finally did, along with Ron and 10 swimmers at the inaugural Swim for Sight. “Every time, it’s a mental game,” she said of the frigid, morning swim. “You jump in, and everyone’s right there. But then everyone scatters, and you feel super alone, and it’s a very surreal, inspiring, amazing experience.”

She swam the 1.5 miles tethered to a guide, as did the three other visually impaired swimmers who participated this year.

Although Ari and Noah play water polo at the Marin Academy and are thus strong swimmers, Ari said the experience was humbling. “You swim until you can’t swim anymore, basically,” he said. “Even today, it’s like: I did that! I couldn’t believe I did it, but I did it.”

Organizing the event with Noah also was challenging. The brothers started planning a year in advance and had to learn everything — from how to write solicitation emails to understanding currents and tides to picking a day for the safest conditions. They also had to recruit swimmers, seek out sponsors, pay invoices, purchase insurance and reserve a boat.

“The lessons I learned will help me in my life in general,” Noah told J. in a separate interview.

The brothers got their water polo teammates to sign up. Their rabbis at Emanu-El, Sydney Mintz and Ryan Bauer, were returning participants. Bauer, in fact, has participated in every Swim for Sight event since the first one 12 years ago.

Bauer said he does the swim because it provides an opportunity to change people’s lives, including Lorie’s. It also helps answer the question: “What can we do to walk with you on this journey?”

Bauer was so determined to participate this year that he rearranged his complicated High Holiday schedule. A pre-dawn Rosh Hashanah men’s mikvah dip at Baker Beach was moved to Aquatic Park so he and some synagogue members could get on the boat heading to the starting spot on Alcatraz. Then, after he finished, Bauer had just enough time to high-tail it to the synagogue to lead second-day Rosh Hashanah services.

“I got out of the water, gave people hugs, ran to my car, put my [clothes] on, and was on the bimah by 10 a.m.,” he said.

Swimmers this year included a 13-year-old boy from San Francisco who swam on behalf of his father, who had sudden vision loss in one eye, and of his aunt, who has RP. Another participant was Los Altos resident Levy Gerzberg, a 78-year-old native of Israel who has now made 100 swims between Alcatraz and the mainland. Ophthalmologists from UCSF swam on behalf of patients.

When asked what was more difficult, preparing for his bar mitzvah or organizing this year’s Alcatraz Swim for Sight, Ari said the fundraiser took more stamina. And unlike his bar mitzvah, it wasn’t for him, Ari said. “It was for awareness,” he said.

The work was also a way to honor their mother, Noah said. “She’s one of the hardest working, most resilient people I know, and she’s taught me all these lessons and [those] qualities in my own life,” he said. “It felt really good to give back to the cause that she’s been working so hard for.”