His early service years included duty as an officer on board the steam sloops-of-war Pensacola and Plymouth, both on the Pacific Station, and the paddle steamer Powhatan in the Atlantic.Promoted to Master in 1881 and Lieutenant in 1887, during much of that decade he had training ship duty in Saratoga and Minnesota, served in the South Atlantic Squadron on the steam sloop Brooklyn, and was twice assigned to the Bureau of Ordnance in Washington, D.C.In 1888-1890 he was involved in the trials of the Vesuvius, whose large caliber compressed-air guns were then considered a promising experiment, and was in charge of installing electric lighting in the new cruiser Philadelphia.He held many responsible positions on shore and at sea, serving as an Inspector of Ordnance, Executive Officer of Yorktown and the battleship Massachusetts, Commanding Officer of the monitor Arkansas and cruisers Minneapolis and Tennessee, had recruiting duty, served as Captain of the Yard at the Philadelphia Navy Yard, attended the Naval War College and was a member of the Navy's General Board (1911) and the Army-Navy Joint Board, among other assignments.Fiske worked out the mechanics of carrying and releasing an aerial torpedo from a bomber, and defined tactics that included a night-time approach so that the target ship would be less able to defend itself.On March 5, 1922, an article appeared in the New York Times stating that "Rear Admiral Bradley A. Fiske, has turned his inventive genius to the literary field and has produced an instrument designed to revolutionize the reading of books.A roller attached to the frame is moved by the forefinger to bring the reading matter steadily in line with the eye.Though Fiske's intention was to allow a reader to carry a small library of books in a purse or pocket, his invention never caught on.