Greenwich resident Aaron Kwittken spent his Saturday morning raising money to fight cancer by swimming 10 kilometers across the Long Island Sound.

Kwittken started in Glen Cove, Long Island and swam to Larchmont in Westchester – a trip that took him three hours and 57 minutes.

"People who know me know that I'll do it and get it done, people who don't know me as well think that I'm absolutely bonkers and crazy," Kwittken laughed after getting out of the water.

"I know he's not [crazy] because he's a very strong swimmer, and I have faith in him that he's always going to do what he has to do to finish the event," his wife Tessa added.

That was especially true Saturday, with Kwittken taking part in Swim Across America – a nationwide program where each swimmer also raises money to fight cancer.

"Any time I do any endurance event, especially because if it's for charity, I always get a little - as my mother used to say - verklempt - I get a little emotional at the end," Kwittken said.

That was especially true here, with a cause so close to his heart. Kwittken is a two-time skin cancer survivor himself, his sister is also a cancer survivor, and he lost a close friend to cancer in 2013.

"It reminds you that it's a privilege to be able to do this," said Kwittken. "And any pain you might have doing an event like this, is nothing in comparison to the pain that people go through."

Organizers say Saturday's Swim Across America - Long Island Sound event raised more than $2 million total, a Swim Across America single-event record, with over $6,000 of that coming from Kwittken alone.

Of all the people taking part around the country, Kwittken is one of the very few who opt for the full 10K swim - which is the longest option participants can sign up for.

"You know there's an end to it, and sometimes there's no end for the people who are battling cancer. It's kind of like life - you don't know what's come at you, you just have to be resilient and be prepared for it, and work through it," he said.

Besides swimming Kwittken also runs, bikes and does iron man competitions - raising money for different charities with each of them.