The 6"/30 caliber gun Mark 1 were used for the primary battery of the United States Navy's dispatch vessel Dolphin with the Mark 2 being used in the secondary batteries for its "New Navy" protected cruisers Atlanta, Chicago, and Boston and the Mark 3 used for the primary and secondary batteries in the succeeding early protected cruisers in addition to secondary batteries in the "Second Class Battleships" Maine and Texas.

USS Dolphin (PG-24) was a gunboat/dispatch vessel; the fourth ship of the United States Navy to share the name. Dolphin was the first U.S. Navy ship to fly the flag of the president of the United States during President Chester A. Arthur's administration, and the second Navy ship to serve as a presidential yacht.