The ferry M/V Wenatchee was pulled from the Bainbridge Island-Seattle route Wednesday night after the crew discovered the vessel had a bent propeller.
Ian Sterling of Washington State Ferries said the ferry likely hit a submerged log.
WSF plans to repair the boat in the water Friday.
The Wenatchee was replaced on the Bainbridge run by the M/V Walla Walla.
The Walla Walla carries 188 vehicles, while the Wenatchee has a 202-vehicle capacity.
WSF said the Walla Walla will stay on the Bainbridge route until the Wenatchee is fixed.