Cafaro says she was told it is a way for the troops to thank them. But she says it's actually the other way around.
"They said they want to say thank you to us, but we're going to say thank you to them for putting their lives on the line and serving our country," Cafaro said.
Cafaro won gold in the Women's 8+ event in both 2008 and 2012 while Petri,a four-time Olympian, helped the American win gold in London.
Cafaro and Petri, who have each gotten involved in other philanthropic causes since becoming Olympians, both actively sought out the trip to Afghanistan. The tour will last 10 days.
"I'm really excited I'm getting to go have this experience," Petri said. "I don't think a lot of us understand their lives. They afford us the right to compete. It's a way to go over there and say thank you."
In the days leading up to her departure, Petri had a message on her Facebook page asking people to e-mail her thank-you letters to distribute to the troops. Some of those who contributed letters are the members of Cal's current women's water polo team.
Petri has been busy since returning from London. In October, she took part in a swim across the San Francisco Bay to benefit cancer research. Then in November she visited underprivileged communities in Rwanda and Uganda to work with "Right To Play," an organization that attempts to empower and educate children facing adversity through play.
After her swim in the Bay, Petri was afforded the opportunity to visit the hospital the raised funds would actually go to, meeting patients and doctors and learning how the money would be used.
In Uganda, she visited refugee camps on the border of Congo where she said "thousands of kids were trying to learn and play and be kids."
"You hear about these things, but actually seeing them in person blew me away," Petri said. "To hear their testimonials was incredible."
Cafaro, along with some of her boat mates, visited the Walter Reed Hospital after winning gold in 2008. It's those kind of experiences that motivate her to pursue the experience she is currently undertaking.
"That was kind of my first validation that what I was doing isn't just selfish," Cafaro said. "It was a moment that was bigger than me. So to go over and thank them for serving our country, I'm so pumped and ready to go."
Cafaro also has recently gotten involved with "Transition Possible," a San Antonio-based organization that works with wounded veterans and adaptive athletes to provide the means for them to continue to be involved with athletics and lead productive lives. After returning from Afghanistan, Cafaro is immediately flying to San Antonio to for an event.
"I think it can only make me a better and more understanding person," Cafaro said. "I hope to make it a part of me. Everybody has their philanthropic causes. This is another way for me to serve my country."