Grade 10 – Nautical Science

December 15, 2020

Flags

The use of signal flags goes back a long way and was made famous by Nelson shortly before the battle of Trafalgar. Although not so extensively used today, flags as a limited means of communication has managed to survive. The merchant navy make use of a total of 40 individual […]
December 15, 2020

Semaphore and flashing light

Semaphore. Semaphore is a means of signalling employing two hand held flags held in various positions relative to the communicator’s body. The flags used are the same, ie flag OSCAR (flag diagonally split by the colours red and yellow. This form of communicating is virtually obsolete today but it may […]
December 15, 2020

Pyrotechnics, amplified voice, ship’s siren and underwater telephone

Pyrotechnics. By pyrotechnics is meant the use of flares of different colours as a means of conveying certain meanings. For example, if a vessel fires a red flare it means internationally that it is in trouble and requires assistance. The use of various coloured flares is mainly used by the […]
December 15, 2020

Radio communications

Radio communications are the the most commonly used means of communication today. It is the easiest to use and the most versatile. It requires no particular skill and it has tremendous range. In addition, it supports a multitude of types of communication, ie telephony (voice), telegraphy (morse), facsimile (reproduction of […]
December 15, 2020

Vessel identities, time, words & phrases and phonetic alphabet

Vessel identities. Vessels identify one another either by their name or international call sign. The name is obviously given to the ship when it is launched. The call sign is allocated by the department issuing the vessel’s radio licence/certificate, usually by the country in which the ship is registered. A […]