
Nearly 200 swimmers and volunteers took to the waters of Pleasure Bay on Saturday to swim, celebrate, and fundraise for cancer research.
The event, which supported the Dana-Farber Cancer Institute and Mass. General Cancer Center, celebrated its 30th anniversary off of Castle Island in South Boston. Swimmers choose between a variety of distances, including a half mile, mile, and two-mile. Participants can also participate in a virtual swim, where they donate, get Swim Across America merchandise, and exercise at home.
Boston’s annual swim is hosted by Swim Across America, a national non-profit that raises money for cancer research and hosts fundraising events in cities across the country. Jamie Mannion, a Swim Across America board member and the director of Boston’s event, said that Saturday’s swim was a far cry from the event’s early years.
Originally, Mannion said, Boston’s event took place on a boat in Boston Harbor, where swimmers would swim in heats in relay races towards Boston Light, the harbor’s lighthouse.

After the pandemic, the group decided to relocate its annual swim to Castle Island in order to accommodate more swimmers.
“One of the things that I love about Boston is that the location is really unique,” Mannion said. “You can see the entire city and you’ve got planes flying overhead.”
Almost 200 swimmers and 100 volunteers participated in Saturday’s swim, Mannion said. The Boston swim was able to fundraise $525,000, the organization said in a statement to the Globe.
Since it began in 1996, Boston’s Swim Across America event has raised over $8.5 million to support cancer research, according to the organization’s website.
Nationally, Swim Across America has raised more than $100 million since its founding in 1987, the Globe previously reported.
The money raised for Saturday’s swim is split between Dana-Farber’s Cancer Institute, the original beneficiary of the event, and Mass. General’s Cancer Center, which partnered with Swim Across America nearly 12 years ago, Mannion said.
Janel Jorgensen McArdle, chief operating officer of Swim Across America, said that at Mass. General, the fundraised money goes to a research team led by Dr. Bryan Choi to fund a clinical trial focusing on glioblastomas, which are highly aggressive, cancerous tumors found in the brain or spinal cord.
At Dana-Farber, McArdle said, the fundraised money supports the hospital’s adult survivorship program, which helps patients who suffer from cancer-related illnesses after successful cancer treatment.
McArdle, a former Olympic swimmer, has worked with Swim Across America for 35 years and was first introduced to the organization at an event in Nantucket.
“It became the highlight of my year every summer, just to be with these people,” McArdle said, “The people that are involved with Swim Across America, it’s all one big family.”
At Saturday’s swim, McArdle worked as an Angel Swimmer, using her Olympic skills to help others participate.
As an Angel Swimmer, “you go with someone that’s maybe not so comfortable in the open water and you swim by their side and make sure they’re ok,” McArdle said.
“We want everyone to have a great experience out there,” McArdle said, “not only in knowing they’re doing something that’s going to be incredible in the course of the cancer world, but also, they’re doing something incredible just as a community of people.”

Days after his mother’s cancer diagnosis in 2023, Dalton Sousa signed up for the Boston swim to raise money for cancer research — it was his way of “giving back,” just as his mom had always taught him.
Saturday morning, Sousa and about fifteen of his high school and college friends joined him in the water. The team completed a two-mile swim, which took them around 45 minutes.
“One day, I’d love to never have to swim again, because we finally found the cure,” he said. “Until that point, we’re going to be around to keep swimming and raising money.”
This year, his team raised over $13,000, bringing his team’s total over the three years to $63,000. Next year, Sousa hopes that the total will reach $100,000.
“The main goal is to raise money for cancer research. Everyone there is doing their best to have fun and just have an enjoyable experience,” he said.
Mannion, Boston’s event director, said that in addition to money raised by swimmers and teams, donations can be made on the Swim Across America website through October.
“It’s always been about the people,” Mannion said, “and it’s always going to be about the people.”
Globe Correspondent Jessica Ma contributed to this report.