The M/V Wenatchee was about half way on its 1:10 p.m. crossing from Bainbridge Island to Seattle's Colman Dock when a witness spotted the woman go overboard, ferry officials said. The witness alerted the ferry crew and two rescue boats were immediately dispatched.
The ferry Tacoma was summoned to leave early from Colman Dock while the ferry Kitsap left its Bremerton crossing to aid in the search.
A few minutes later, the woman was spotted and brought onto a Coast Guard boat, officials said. The woman was then brought to a waiting ambulance at the Coast Guard base on the southern Seattle waterfront where she was taken to Harborview Medical Center in stable condition.
Ferry officials say regular ferry service has since resumed.