Detached from the Atlantic Squadron on 7 May 1897, "Amphitrite" served as a training ship for the instruction of gun captains. As such, she was apparently placed in ordinary at Norfolk, since she was not recommissioned until 2 October 1897, with Capt. Charles J. Barclay in command. The men she placed in service soon proved to be invaluable in the war with Spain. Some 45 trained gun captains "who had received exact training fit to match the modern gun", gave a "good account of themselves" in action against Spanish ships. Clearing Hampton Roads on 5 October, the monitor visited New Bedford, Massachusetts, from 7–23 October, and Tompkinsville from 24 October-12 November, before she returned south, to Lambert's Point, Virginia, arriving on 14 November.