Owing to her light draft and steady platform, Amphitrite was deemed well adapted for gunnery work, and received on board two classes a year consisting of 60 men. From 1 July-4 October 1899, the monitor carried out gunnery instruction out of New Bedford, and on 12 October sailed for the New York Navy Yard for necessary repairs. Upon completion of this yard period, Amphitrite sailed for Port Royal on 3 December, stopping en route at Norfolk for coal and ammunition. Arriving at her destination on 9 December, she commenced her gunnery training course nine days later. On 17 January 1900, the tug was turned over to Amphitrite and fitted with a battery of one 6-pounder and one 1-pounder; for the remainder of the course, the tug proved a valuable adjunct to the monitor, serving as an "economical, handy, and effective moving platform" for moving subcaliber practice. Amphitrite completed her work at Port Royal on 19 April and proceeded north, accompanied by Chickasaw, stopping at Norfolk en route, and reached Tompkinsville on 9 May, proceeding thence to New Bedford, arriving there on 14 June. The tug subsequently replaced Chickasaw as Amphitrites tender, joining the monitor off New Bedford on 25 June 1900.
