Having mastered command of the eastern Mediterranean skies, the ship switched focus to honing her gunnery skills. She fired live rounds from all her guns – from the main 4.5in gun on the forecastle to the automated 30mm gun, the Phalanx automatic Gatling gun which spews 20mm rounds at incoming fast-attack craft and missiles at a rate of 3,000 per minute, down to small arms, Diamond’s last line of defence against all attackers.