The U.S. Coast Guard was responding this past weekend to a cargo ship adrift off the Northern California coast, authorities said.
The ship Wan Hai 176 experienced engine problems Friday afternoon while about 12 miles (19 km) off Point Reyes in Marin County, the Coast Guard said in a statement.
The 564-foot (172-meter) container ship was unable to properly anchor and was moving closer to shore, the statement said.
The ship managed to deploy a second anchor that held, and it remained about 7 miles (11 km) from the coast on Saturday, officials said.
Three tug boats were dispatched but they were unable to deploy lines to tow the ship because of rough seas, according to the Coast Guard.
There were no reports of injuries.
Coast Guard helicopter crews were dispatched to monitor the area. Officials with the California Department of Fish and Wildlife Office of Spill Prevention and Response and Marin County were also on scene.
The Singapore-flagged vessel with 21 people on board is carrying nearly 800 containers with various cargo, the Coast Guard said.