The signal is composed of seven or more short blasts followed by one long blast on the ship's whistle and internal alarm system. Within 24 hours of embarkation of all passengers, the crew will conduct a mandatory muster drill in which the General Emergency Signal is sounded. The purpose of the drill is to educate passengers of emergency procedures should an actual emergency occur. The signal alerts passengers of an emergency so that they will begin proper procedures in which all persons collect their life jackets and proceed to their assigned muster stations.
There is also an abandon ship alarm which is used should it become necessary to abandon ship, after all other efforts have been exhausted. This signal is given audibly by the ship's Master over the PA system. It is never given by automatic means or with recorded media.
The LSA defines the characteristics of the general alarm signal. The alarm signal itself is seven or more short blasts followed by one prolonged blast on the ship's whistle.
Requirements on General Alarm Systems according to the Safety Of Life At Sea (SOLAS) Convention:
The alarm must be powered by the ship's main electrical supply and also by the emergency supply. It must continue to operate automatically unless turned off or over-ridden. The alarm signal is given both by the ship's whistle (or siren) and by onboard bells and klaxons.
The alarm must be loud enough to be heard in both interior and exterior spaces. The minimum volume is defined both as an absolute value and also as a value louder than normal sounds in the area. It must be loud enough to wake sleepers in cabins.
- International Maritime Organization 1998, §188.8.131.52.
- International Maritime Organization 1980, chapter III, regulation 34.
- International Maritime Organization 1998, §7.2.1.
- International Maritime Organization 1998, §184.108.40.206.
- International Maritime Organization 1998, §220.127.116.11.
- International Maritime Organization 1998, §7.2.2.
- International Maritime Organization (25 May 1980), International Convention for the Safety of Life at Sea (SOLAS), 1974, as amended, retrieved 18 July 2020
- International Maritime Organization (1 July 1998), Life saving appliances (LSA) code (PDF), retrieved 18 July 2020