"Galatea"s main armament consisted of two breech-loading (BL) Mk V guns, one gun fore and aft of the superstructure on pivot mounts. Her secondary armament was ten BL guns, five on each broadside. Protection against torpedo boats was provided by six quick-firing (QF) 6-pounder Hotchkiss guns and ten QF 3-pounder Hotchkiss guns, most of which were mounted on the main deck in broadside positions. The ship was also armed with six 18-inch (457 mm) torpedo tubes: four on the broadside above water and one each in the bow and stern below water.