"Ocean" had a main battery of four 35-calibre guns mounted in twin-gun turrets fore and aft; these guns were mounted in circular barbettes that allowed all-around loading, although at a fixed elevation. The ships also mounted a secondary battery of twelve 40-calibre guns mounted in casemates, in addition to ten 12-pounder guns and six 3-pounder guns for defence against torpedo boats. As was customary for battleships of the period, she was also equipped with four torpedo tubes submerged in the hull.