"Undine" joined the Mississippi Squadron and, in May 1864, was deployed in the Mississippi River between Fort Adams and Natchez, Mississippi. She soon left the Mississippi and operated during early July in the Tennessee River in support of Union forces ashore. While standing off Clifton, Tennessee, "Undine", Acting Master John L. Bryant in command, struck a snag and partially sank on 25 July. Her crew was able to transfer the ship's guns ashore to defend Clifton from Confederate attack before taking measures to raise the vessel. "Undine" was successfully refloated on 1 August after the arrival of the pump steamer "Little Champion" on 31 July.