The Ship Security Alert System (SSAS) is provided to a ship for the purpose of transmitting a security alert to the shore to indicate to a competent authority that the security of the ship is under threat or has been compromised.^[1] In case of attempted piracy or terrorism, the ship's SSAS beacon can be activated by the crew to continuously send silent alerts to predefined recipients. Technically, the SSAS consists of a GPS receiver linked to a transmitter, a power supply, software and activation buttons.^[2]

There must be at least two independent activation points on the ship, one on the navigation bridge and the other(s) in places immediately accessible by the crew, such as the engine room, master's cabin or the crew lounge. When the ship is under attack, the crew can activate the SSAS beacon by pressing a button which automatically sends a message, usually SMS or email, over satellite connection to predefined recipients such as the ship owner, fleet manager and flag state. An SSAS report contains the ship name, unique identification numbers like MMSI, IMO number and call sign, the date and time, the ship's current position, speed and course. No audible or visible alarm is generated while the SSAS report is being transmitted to prevent discovery of the report by the intruders. Once the SSAS button is pressed, the alert will be continuously transmitted to the recipients unless it is reset or deactivated. An SSAS beacon operates with similar principles to the aircraft transponder emergency code 7500.^[3]

The alert receivers are obliged to inform the national authorities of the coastal states where the ship is sailing, so that help from security forces can be dispatched to the location.

The SOLAS Convention (Chapter XI-2, Regulation 6) requires all vessels to be equipped with SSAS. Only exception are non-passenger vessels of less than 500 GT constructed before 1 July 2004.^[4] It is part of the International Ship and Port Facility Security (ISPS) Code that amends the SOLAS on maritime security.