Very few people will recognise these devices and technology today.
Beginning in 1836, the American artist Samuel F. B. Morse, the American physicist Joseph Henry, and Alfred Vail developed an electrical telegraph system. This system sent pulses of electric current along wires which controlled an electromagnet that was located at the receiving end of the telegraph system.
Courtesy: Australian Maritime Safety Administration
Vibroplex brand semiautomatic key (generically called a "bug")
An important application is signalling for help through SOS (Save Or Souls), ” . . . _ _ _ . . . “. This can be sent many ways: keying a radio on and off, flashing a mirror, toggling a flashlight, and similar methods. SOS is not three separate characters, rather, it is a prosign SOS, and is keyed without gaps between characters.
A U.S. Navy signalman sends Morse code signals in 2005.
Upcoming articles in this blog will include information about AIS (Automatic Identification System), VDES (VHF Data Exchange System), AIS Transponders / Transceivers, AIS Class A, AIS Class B, AIS Base Stations, AIS AtoN (Aids to Navigation), AIS SART (Search and Rescue Transmitter), Vessel Traffic Service (VTS), Vessel Traffic Management Information System (VTMIS), AIS Satellite, Global Maritime Distress and Safety System (GMDSS), Digital Selective Calling (DSC), Marine VHF Radio, Homeland Security, Exclusive Economic Zone (EEZ), cargo payload, draught, capacity utilisation, maritime big data, bulk shipping, line-up reports, trade flow, commodity, satellite, naval architecture, fishing, sar, security, synthetic aperture radar, visible infrared imaging radiometer suite (viirs), vessel tracking, ship tracking, communication and other related issues.