December 15, 2020

Communications – introduction

Introduction. Communication plays a very important part in modern society. We have advanced from the days of the old land-line based telephone and postal (snail) mail to mobile phones and e-mail. Technology has given us the ability to communicate with each other instantly and anywhere in the world. It has […]
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 […]