When she dives into Long Island Sound to take part in Swim Across America next week, Abigail Condon will be thinking of her late maternal grandparents Dick and Donna Reynolds, who both died of cancer before she was old enough to know them.

For the 16-year-old competitive swimmer and New Canaan native, the aquatic fundraiser for cancer research will also be her first experience swimming in open water after years on the New Canaan High School swim team and the Greenwich YMCA Marlins Swim Team.

“I wanted to challenge myself with an open swim,” Condon said. “But I also think of my grandfather who passed away of stomach cancer and grandmother who died of lung cancer. I wish I could have had a connection with them.”

Registration is still open for the Ninth Annual Swim Across America Greenwich-Stamford event on Long Island Sound at 10 a.m. June 27 to raise money for cancer research, treatment, and prevention programs. The event includes half mile, 1½-mile, and 3-mile components.

In addition to swimmers, the group is looking for boaters, kayakers, paddle boarders, and other land volunteers to sign up to participate in the event.

The group was founded in 1987 by longtime Darien resident Matthew Vossler, and Jeff Keith, who were Boston College roommates. it is now a national organization and has raised more than $50 million for cancer research programs since the first swim event held between Fairfield and Port Jefferson, N.Y., 28 years ago, Vossler said.

Proceeds from the Greenwich-Stamford event will go to benefit the Alliance for Cancer Gene Therapy based in Stamford, a major foundation which conducts genetic research into cancer treatments.

“It’s cutting edge so this is really the area where the more remarkable solutions or cures are coming from and basically using the body’s own immune system to fight the cancer,” Vossler said. “The alliance is unique in the world in that it was one of the original funders of the gene approach, putting it back on the map for pharmaceutical companies.”

Condon said as part of the Marlins Swim Team, she has taken part in other swims that have helped raise $9,000 toward the cause.

“I’m really happy to be involved,” she said.

In addition to many local residents, the group and event has also attracted the support of well-known aquatic athletes such as Olympic gold medalist Donna de Varona, who is honorary co-chair of the event, and Janel Jorgensen McArdle, a 1988 Olympic silver medalist who is co-president of Swim Across America.

Since it started nine years ago, the swim in Greenwich-Stamford by itself has raised more than $1 million, Vossler said.

“We’ve really made some significant strides with the research and some new therapies coming out of the labs,” Vossler said. “We’ve made a difference.”

Jesse Bass, another New Canaan resident and Greenwich native, will also swim in the event in the half-mile option. It will be his fifth time participating, which he does to celebrate his mother, an ovarian cancer survivor.

Bass said a large part of the appeal of the event is the opportunity for families and friends to rally around someone who has fought or is fighting cancer. Bass’ brother Daniel is flying in from Wisconsin to take part in the event as a kayaker.

“We really look forward to it each year for the camaraderie in addition to supporting some great groups,” Basssaid.

To sign up to swim, volunteer, or donate, visit swimacrossamerica.org/greenwich.