2 FUNCTIONAL REQUIREMENTS

 2.1 General

.1 The functional requirements of the GMDSS are detailed in SOLAS chapter IV, regulation 4.

It is of great safety importance that all requirements laid down are fulfilled. The most important requirement is that "Every ship, while at sea, should be capable of transmitting ship-to-shore distress alerts by at least two separate and independent means each using a different radio communication service". It should be possible to initiate such alerts from the position from which the ship is normally navigated.

.2 Under certain conditions the satellite EPIRB may be used to meet this requirement if installed close to the navigation bridge or if it can be remotely activated from the bridge.

.3 In addition to the above-mentioned requirements, it should be possible to initiate the transmission of DSC distress alerts from the navigation bridge on VHF, and also on MF or HF, provided that the MF or HF equipment is obligatory in the trade area of the ship.

(SOLAS 1974, as amended, regulations IV/8 and 9)

.4 All ships should keep continuous watch on VHF channel 70 by use of a DSC receiver.

.5 Ships with MF requirements should in addition keep continuous watch on MF DSC 2187,5 kHz and on HF DSC distress and safety channels if required to have HF radio equipment installed (see also subsection 4.2.4 and 4.2.5).

.6 By resolution MSC.131(75) the Organization has decided to require all ships to maintain, when practical, a continuous listening watch on VHF channel 16 until such time as the Maritime Safety Committee may determine the cessation of this requirement, taking into account that a re-assessment will be undertaken by the Organization no later than 2005. The Maritime Safety Committee, at its seventy eighth session (May 2004) agreed that listening watch on VHF channel 16 by SOLAS ships, while at sea, should be required and kept for foreseeable future with a view to providing:

• .1 a distress ability and communication channel for non-SOLAS vessels; and

• .2 bridge-to-bridge communications for SOLAS ships.

.7 Watch should also be kept with NAVTEX and/or with EGC receiver. The watch should be kept at the position from which the ship is normally navigated.

(SOLAS 1974, as amended, regulations IV/8, 9 and 12)

 2.2 Sea areas (definitions)

.1 Sea area A1 means an area within the radiotelephone coverage of at least one VHF coast station in which continuous DSC alerting is available, as may be defined by a Contracting Government.

.2 Sea area A2 means an area, excluding sea area A1, within the radiotelephone coverage of at least one MF coast station in which continuous DSC alerting is available, as may be defined by a Contracting Government.

.3 Sea area A3 means an area, excluding sea areas A1 and A2, within the coverage of an Inmarsat geostationary satellite in which continuous alerting is available (76 °N and 76 °S).

.4 Sea area A4 means an area outside sea areas A1, A2 and A3.

 2.3 Equipment requirements (including duplication of equipment) for SOLAS ships

GMDSS equipment requirements in force for all passenger ships in international trade as well as cargo ships of 300 gt. and upwards in international trade:

(SOLAS 1974, as amended, chapter IV and IMO resolution A.702(17))

¹) Outside NAVTEX coverage area.

²) Cargo ships between 300 and 500 gt.: 1 set. Cargo ships of 500 gt. and upwards and passenger ships: 2 sets.

³) Cargo ships between 300 and 500 gt.: 2 sets. Cargo ships of 500 gt. and upwards and passenger ships: 3 sets.

⁴) Inmarsat E-EPIRB cannot be utilized in sea area A4.