A tugboat that disappeared in 1921 was discovered and finally identified late last year by a team of marine surveyors, archeologists, and naval personnel.
The USS Conestoga had set out from the Mare Island naval base, just east of San Francisco, for American Samoa on March 25, 1921.
It never arrived. Instead, just hours after leaving San Francisco Bay the Conestoga ran into a storm and was swamped. Conestoga had a crew of 56 when she disappeared.
Weather records indicate winds had reached speeds of up to forty miles an hour, and another ship had passed a message from Conestoga that it was “battling a storm and the barge she was towing had been torn adrift by heavy seas.”
After the Conestoga was listed as overdue in American Samoa, the Navy began a massive search across the Pacific.
Unfortunately, the search assumed the ship had gone down much farther out to sea than it actually had, with the Navy concentrating its search between Pearl Harbor, Hawaii, where it had a scheduled stopover, and American Samoa. In fact, the wreck was found just 30 miles off the California coast, near the uninhabited Farallon Islands.
The National Oceanic and Atmospheric Administration discovered the sunken wreck in 2009, when a sonar survey of the area around the Farallons turned up a previously undiscovered shipwreck (about 300 ships are known to have gone down off the coast of San Francisco).
Although much of the ship’s superstructure had collapsed over time, the overall layout of the ship was still intact.
Also intact were a number of unique aspects of the Conestoga that helped verify its identity.
The ship’s steam steering gear, Williamson steam-steering engine 4 1/2 by 4 1/2-inch double cylinders, were identified as part of the wreck.
Another clue was a single 3-inch 50-caliber gun discovered on the ship’s bow. This narrowed the ship’s identity down to a naval vessel. Conestoga had been fitted with a 3-inch gun after it had been purchased by the Navy from the coal trade.
NOAA used a Phantom HD2 underwater drone in September 2014 to obtain video of the wreck.
Three survey dives confirmed the wreck was a 170-foot long steel-hulled steam-powered oceangoing tug.
In October of last year a second expedition to the location of the wreck used an unmanned underwater vehicle that penetrated the open hull to gather more information. Based on the data retrieved, U.S. naval officers positively identified the wreck as the Conestoga.
The ship’s location is now protected by the National Marine Sanctuary Act and the Sunken Military Craft Act of 2004, which prohibits the site from unauthorized disturbance.
