Grade 12 – Nautical Science

September 24, 2020

Radio watchkeeping

Radio watchkeeping is automatic with GMDSS. When receiving equipment is activated an operator is alerted. After this, further distress and safety communications are carried out on radio telephone or radio telegraphy (Narrow Band Direct Printing). It should be noted that the previous (specialist) telecommunications officer is now only carried aboard […]
September 24, 2020

GMDSS sub-systems

The GMDSS system is made up of five sub-systems as follows: DSC (digital selective calling) terrestrial communications system. Dedicated frequencies are made available for maritime communications operating in the VHF, HF and MF radio bands. This provides long, medium and short-range communications. Use is made of DSC technology which provides […]
September 24, 2020

GMDSS functions

The GMDSS is designed to perform 9 functions: Transmission of ship to shore distress alerts by two separate and independent means. The details for this function are contained on the individual ship’s radio safety certificate. For example, a ship in area A1 would use VHF DVS equipment as the primary […]
September 24, 2020

Minimum operator requirements for vessels

The minimum operator requirements for vessels is as follows: ships operating within range of a VHF coast station – ROC (Restricted operator certificate). ships operating beyond the range of VHF coastal stations – GOC (General operator certificate). The international convention on STCW require that all deck officers shall hold an […]
September 24, 2020

Knowledge requirements of officers

Deck officers should have the following knowledge/ability: A detailed knowledge of the operation of all GMDSS sub-systems and equipment. The ability to send and receive messages correctly by radio telephone and NBDP. A detailed knowledge of the regulations applying to radio communications. A knowledge of the documents relating to the […]