Citadel

A citadel is a hardened, pre-designated refuge aboard a merchant ship into which the crew withdraws during a piracy boarding, denying attackers control of the vessel and buying time for naval response. An effective citadel under BMP guidance has independent communications to UKMTO and the company, food, water, and emergency steering or engine control, and a structure that resists forced entry. Naval forces will generally only attempt a recapture if they can confirm the entire crew is secured inside.