As per SOLAS chapter II- 1, Regulation 6
All ships shall be provided with a ship security alert system, as follows:
- Ships constructed on or after 1 July 2004;
- Passenger ships, including high-speed passenger craft, constructed before 1 July 2004, not later than the first survey of the radio installation after 1 July 2004;
- Oil tankers, chemical tankers, gas carriers, bulk carriers and cargo high-speed craft, of 500 gross tonnage and upwards constructed before 1 July 2004, not later than the first survey of the radio installation after 1 July 2004; and
- Other cargo ships of 500 gross tonnage and upward and mobile offshore drilling units constructed before 1 July 2004, not later than the first survey of the radio installation after 1 July 2006.