Inmarsat satellite system for transmission of navigational and meteorological warnings to ships, complementary to the International NAVTEX service on 518 kHz. The ability to receive SafetyNET service information will generally be necessary for all ships which sail beyond the coverage of NAVTEX.

Search and Rescue.

Communications necessary for the coordination of ships and aircraft participating in a search and rescue operation.

Search and Rescue Radar Transponder. Also known as a survival craft radar transponder or radar transponder.

An identification number, 5 digits for ship stations and 4 digits for coast stations, programmed into NBDP (telex) equipment. In the ALRS Volume 1, the coast station Selcall is shown in square brackets, Guam [1096]. It is only required generally for ARQ mode of operation.

Super High Frequency (3 to 30 GHz).

An earth station in the maritime mobile

A station in the terrestrial radio

Operating method in which transmission is made possible alternatively in each direction of a telecommunication channel, for example, by means of manual control (see single

The same frequency used for transmission and reception (simplex).

Standard Marine Communication Phrases.

Safety of Life at Sea. International Convention for the Safety of Life at Sea.

Safety of Life at Sea Convention as adopted by the IMO, and accepted by contracting governments.

Ship Security Alert System. A system fitted under Regulation 6 of SOLAS chapter XI

Single Side Band mode of emission using amplitude modulation, where one sideband is reduced, suppressed or fully removed.

Sea Safety Message. A type of coastal warning referring to hazards which are considered to be of a temporary nature, eg. floating logs, temporary buoys, etc, usually broadcast for a defined period.

Short Safety Related Messaging. A text

Seafarers’ Training, Certification and Watchkeeping (Code and International Convention on).