The USS R-20 (SS-97) was an R-class coastal and harbor defense submarine laid down on 4 June 1917 by the Union Iron Works in San Francisco, California. It was launched on 21 January 1918 sponsored by Mrs. Arnold Foster and commissioned on 26 October 1918 with Lieutenant Commander Alfred E. Montgomery in command. The submarine was decommissioned at Key West on 27 September 1945 and struck from the Naval Vessel Register the following month. On 13 March 1946, she was sold to Macey O. Scott of Miami, Florida. The submarine is suspected to have contained asbestos after 1941 when it was put in use again following being decommissioned for approximately 10 years. Asbestos, the carcinogenic mineral was most likely present in the wall insulation of the submarine. We advise everyone who served in the US Navy prior to 1980 to pay close attention to their health so as to prevent a serious disease such as lung cancer, mesothelioma, or asbestosis, from developing.