West Coast regional maritime heritage coordinator for NOAA's office of National Marine Sanctuaries
Robert Schwemmer coordinates maritime heritage activities for the five national marine sanctuaries along the Pacific West Coast, which is approximately 14,000 square miles of seafloor. He conducts historic research and archaeological surveys using various methods to gather data, including scuba divers, manned submersibles, remotely operated vehicles and autonomous underwater vehicles. He shares his research with the public through outreach events and the development of exhibits for learning centers and museums. A recent survey led to the discovery of a long-lost U.S. Navy vessel that disappeared without a trace in 1921, taking 56 officers and sailors down with it.
SEA: Could you tell us a bit about the history of USS Conestoga?
Schwemmer: USS Conestoga (AT 54), was originally built as the civilian tugboat Conestoga at the Maryland Steel Co. at Sparrows Point, Baltimore, Md., for its owner, Philadelphia and Reading Railroad Co. Newspaper headlines reported it was one of the largest and most powerful seagoing tugboats on the Atlantic Ocean. The launching was so newsworthy, Marine Engineering, in August 1904, featured story and included the ship’s plans and detailed information on the tugboat’s construction that was useful in the ROV surveys in September 2014 and October 2015 aboard the research vessel Fulmar in Greater Farallones National Marine Sanctuary.
Conestoga was requisitioned by the U.S. Navy in 1917 for military service during World War I. It was converted into an armed tug to support the Allied war effort at home and abroad in the Atlantic. Conestoga was assigned to the submarine force and was engaged in towing duties along with transporting supplies and serving as an escort for convoys headed to Bermuda and the Azores. For a brief time, it was also stationed in the Azores where it helped patrol the surrounding waters for German U-boats, known as the first Battle of the Atlantic. After World War I, the tug was reassigned to be the station ship for the U.S. naval station at Tutuila, American Samoa. After its outfitting in Norfolk Naval Shipyard in Virginia, the tug transited to San Diego and then on to Vallejo, Calif., for final preparations for its trip to American Samoa via Hawaii. On March 25, 1921, Conestoga departed Mare Island, passed San Francisco, exited through the Golden Gate and was never heard from again. USS Conestoga is one of 18 U.S. Navy ships lost with all hands between 1780 and 1921 as well as the last of only four U.S. Navy ships lost in peacetime without a trace in the 20th century.
Was the search ongoing, or did a recent event spark new interest in finding the lost vessel after so many years?
The U.S. Navy conducted the first sea and air search for Conestoga off the Hawaiian Islands from the island of Oahu extending to Midway Atoll as well as off Lower (Baja) California where a whaleboat (lifeboat) with a single letter “C” was discovered — in total, some 400,000 square miles. This was the largest sea and air search until the disappearance of Amelia Earhart over the Pacific 16 years later. On June 30, 1921, the U.S. Navy officially declared Conestoga lost with her crew of 56. For the next 93 years there were no reported searches for Conestoga, including by NOAA. Conestoga remained one of the top 10 unsolved shipwreck mysteries, vanishing without a trace and believed to be lost in the deep Pacific somewhere off the Hawaiian Islands. In 2014, the first year of a three-year maritime heritage mission to inventory and survey ship and aircraft losses working on board the research vessel Fulmar in the Great Farallones National Marine Sanctuary began. Principal investigators include myself and James Delgado, Ph.D., conducting ROV surveys on multiple multibeam and side-scan sonar targets, one of which was a likely shipwreck off Southeast Farallon Island recorded by NOAA’s Office of Coast Survey in 2009. We needed to determine the pieces of evidence that could lead us to answering the identification of this shipwreck. At the time of the investigation, three survey dives were made to fully characterize the sonar target; we determined the recently charted shipwreck was a 170-foot seagoing tugboat from the late 19th or early 20th century. After a check of my shipwreck database, we found no large steel-hull steam powered tugboats reported lost in Greater Farallones sanctuary, and it was labeled as the “mystery tug.”
What was most remarkable about the find?
What was really remarkable about this discovery is that after one of the largest U.S. Navy sea and air searches in the 20th century, the large seagoing tugboat had only made it approximately 30 miles outside the Golden Gate and remained uncharted for 88 years, and it took 93 years to identify the wreck. We can now honor the brave crew and their military grave site, bringing closure to their families who waited 95 years to learn of the final resting place within sight of the California mainland. Today, family members are sharing photographs of their lost loved ones, finally putting faces to the long list of names. What an honor not only to share their story with the American people, but more importantly to share Conestoga’s final fate with the crew’s families, a story that has been passed down through generations.
What were some challenges in accessing the shipwreck?
There are strong currents and low surface visibility during foggy conditions. During the surveys, we are faced with both surface and deep-water currents, sometimes flowing in opposite directions, and underwater visibility can drop when the sea state worsens or after a storm. We “live-boat,” never dropping an anchor, so during the surveys the captain of Fulmar is constantly repositioning the vessel to follow the tethered cable connected to the ROV as it surveys the wrecks. When the current is strong or there are wind gusts, there are multiple adjustments that have to be made during the survey. During the September 2014 expedition, we used a larger Phantom ROV to conduct the survey, but it was too large to survey the interior of the shipwreck. During the October 2015 expedition, we partnered with Teledyne SeaBotix, which provided a technician and a mini-ROV that allowed careful examination of the inner hull, including surveying a key diagnostic artifact that identified the wreck as Conestoga: the three-inch 50-caliber naval gun resting on a lower deck in the forecastle. The gun was a match to the photograph of the same gun taken on board Conestoga in 1921. Teledyne also provided a BlueView sonar that provided high-resolution imaging and measurements of the hull to get confirmation they were a match to the measurements noted on the original ship’s plans.
Any personal thoughts about the discovery after almost a century?
Conestoga isn’t just a ship. It is a tangible reminder of who we are as a nation. The crew of Conestoga represented diverse communities and cultures across America, united in a cause bigger than themselves. When Conestoga disappeared it tore a hole in the fabric of many families that has lasted generations. Now that hole can start to be mended with the knowledge that Conestoga has been found in a national marine sanctuary, where it will continue to be protected by law and in turn provide sanctuary for marine creatures.