Rivalen, a 43-foot motor pleasure craft, was built at Neponset, Massachusetts, in 1916. Leased by the Navy in April 1917 for use as a patrol boat, she did not actually begin active service until May of the following year. The boat was soon found to be unsuitable for operation and was laid up in July 1918. Rivalen was returned to her owner in May 1919. Her name was changed to Tremont in 1921, and she remained in use as a pleasure craft into the 1930s.