NOAA and its partners released 3D sonar maps and images of an immigrant steamship lost more than 100 years ago in what many consider the worst maritime disaster in San Francisco history.
On Feb. 22, 1901, in a dense morning fog, the SS City of Rio de Janeiro struck jagged rocks near the present site of the Golden Gate Bridge and sank almost immediately, killing 128 of the 210 passengers and crew aboard the ship.
Top - CodaOctopus 3-D Echoscope sonar profile view of SS City of Rio De Janeiro. Credit: Coda Octopus/NOAA Bottom - Painting of SS City of Rio De Janeiro. Credit: Mystic Seaport
NOAA’s Office of National Marine Sanctuaries Maritime Heritage Program is engaged in a two-year study to discover and document shipwrecks in Gulf of the Farallones National Marine Sanctuary and nearby Golden Gate National Recreation Area. In November, Hibbard Inshore and Bay Marine Services donated a research vessel and crew, along with a high-powered remotely operated vehicle, to help NOAA pinpoint and map the City of Rio de Janeiro wreck site using a three-dimensional Echoscope sonar developed by CodaOctopus.
During this expedition, Robert Schwemmer, West Coast regional maritime heritage coordinator for NOAA's Office of National Marine Sanctuaries, worked with multibeam sonar expert Gary Fabian to locate the wreck site again. They located the site in 287 feet of water, positioned inside the main ship channel, and largely buried in mud. Schwemmer and the Hibbard team captured the first detailed sonar and three-dimensional images of City of Rio resting in the dark, muddy waters outside the bridge. The team also completed the first detailed map of S.S. City of Chester, which was re-discovered late last year in the vicinity of City of Rio.
“The level of detail and clarity from the sonar survey is amazing,” Schwemmer said. “We now have a much better sense of both wrecks, and of how they not only sank, but what has happened to them since their loss.”
Blair Cunningham, president of technology, CodaOctopus Products Inc., said “We are extremely pleased the Echoscope has proven to be an excellent archaeological tool, providing unrivalled imaging. We look forward to working with NOAA National Marine Sanctuaries in the future.”