Refitted during the winter of 1806-07, she set a record of 14 days on an eastbound run from Cape Henlopen, Delaware, to the mouth of the River Mersey (Liverpool, England) in May 1807.
Converted into a whaler
She was eventually taken out of general trading service; refitted as a whaler, and, by 1850, was sailing from New Bedford, Massachusetts, on extended voyages to the South Atlantic Ocean and to the Pacific Ocean.
Still operating at the outbreak of the Civil War, Rebecca Sims was acquired by the Union Navy at Fairhaven, Massachusetts, on 21 October 1861 for use in the Stone Fleet, the ships which were to be sunk as obstacles in the shipping channels of the South's major ports.
The whaler was stripped of all unnecessary equipment; filled with stone; and, under the command of her previous master, James M. Willis, sent south in late November. In early December, she arrived off Savannah, Georgia, whence, at mid-month, she proceeded to Port Royal, South Carolina. On 19–20 December, she and 16 other ships were sunk in the main channel of Charleston Harbor.
