The crew expects to spend about five days aboard Johnson’s sailboat, Blue Moon, before reaching the spot where Madsen's boat is likely to be.
Johnson estimated they would need three days to find Row of Life and secure it to Blue Moon, and then another five days or more to tow the 19-foot (5.8-meter) craft to Diamond Head in Honolulu, where Madsen planned to finish her journey.
Madsen was forced to use a wheelchair beginning in 1993 after a back surgery.
She competed three times for the U.S. in the Paralympics, winning a bronze medal in the shot put in 2012 and taking seventh with her rowing partner in 2008.
Madsen was attempting to become the first paraplegic and oldest woman to row across the Pacific Ocean.
Madsen’s wife, Debra Madsen, attended the crew's departure from the Hawaii Yacht Club, which helped organize the mission. One of the primary goals is to recover personal items remaining on Row of Life, including a video diary of the journey.
“There’s a lot on that boat," Debra Madsen said. “Her last 60 days of memories.”