How would the Royal Navy use dual-purpose guns if a ship faced air and surface attack at the same time?
Short answerIt would engage the most immediate threat first and split batteries when arcs and fire-control arrangements allowed useful simultaneous fire.
NotesDual-purpose guns cannot engage every threat equally merely because they can fire at both aircraft and ships. The first priority is the attacker that presents the most immediate danger to the vessel. Separate port and starboard batteries may divide their work when the threats lie in different arcs and directors can support both engagements. Concentrating on one target can still be necessary when fire-control channels, ammunition handling, or geometry make divided fire ineffective.