SEATTLE - He's returned home victorious, an Olympic Gold medalist again. But Nathan Adrian has not yet fulfilled a promise to participate in an aquatic event near his hometown.

"I'm signed up for the half mile swim," the Bremerton native and three-time Olympian said with a laugh on Thursday, "definitely the first race since Rio."

It was a promise he made to his long-time friend and college teammate Matt Benoit.

"I remember getting a call in my car and him saying man, let's do this," recalled Adrian on Thursday.

Benoit was a three-time All-American swimmer at Kennedy High and went on to qualify for the Olympic trials while swimming alongside Adrian at the University of California Berkeley.

"Every father thinks their kid is special. I certainly think he was," said Dan Benoit, who sat near Adrian on Thursday at the Seattle Cancer Care Alliance, recalling a difficult 4 1/2 years for his family.

"This journey," said Dan, started back in 2012 when "my wife (Kalany) was diagnosed with lung cancer and treated here."

She passed away in April of 2013. Matt talked about raising money for cancer research as part of Swim Across America, and enlisted Adrian and his other Cal teammates to participate.

But then "about eight months later, (a) totally different type of cancer he was diagnosed with," said Dan.

In April of this year, Matt Benoit passed away from complications related to Ewing's Carcoma. He was just 28 years old.

"We kinda got the news via text message," said Adrian, who was in the process of preparing for the Rio Olympics. However, he had circled this weekend on his calendar to honor his friend, and raise money to fight the disease.

Swim Across America will be held on Saturday, at 8 a.m. at Luther Burbank Park on Mercer Island. The Benoit family, along with Adrian, have helped to raise more than $400,000 in revenue, which will be donated to the SCCA, where Matt and Kalany received care. There is also a cellular therapy research lab, which bears the SAA name. Dan and Adrian both toured the lab on Thursday. More than 400 swimmers have signed up to participate and filled all the available spots.

"We're trying to raise money and provide seed money - angel money - for doctors who have unique or good ideas that may not be able to get money," said Scott Whelan of Swim Across America.

"The money we raise stays local." It's an event now in its eighth year.

SCCA surgical oncologist and researcher Dr. Vanu Pilarisetty says the money has made strides in cancer research.

"The research work is really critical to how we move our treatment to the same thing we've done for a hundred years," he said. "The work we've been doing in the last five years will help patients (in the near term), we're just getting there."

"We're following through with his goal," said Dan Benoit about his son and the plans this weekend. "Celebrate him and his life, and that's what we plan on doing."

Adrian will also fulfill that promise to a friend and swim Saturday morning.

"Matt was the most positive person that I had ever met or seen go through an experience like this," said Adrian. "Matt has an an amazing impact on all of our lives."