Radio telecommunication at sea had undergone a sea change in the last century. After the days of semaphores and flags (which is still relevant today in some cases), radio brought about a drastic change in marine communication at sea.
From the early years of the last century, ships started fitting radio for communicating distress signals among themselves and with the shore. Radiotelegraphy using Morse code was used in the early part of the twentieth century for marine communication.
With the development of mobile communication technology, marine communication has not only used radiotelegraphy but also used wireless telephones for a long time. These wireless telephones are widely used for business contacts, regularly reporting ship positions and entry and exit dates, and following land transfer commands. Seafarers onboard can also use wireless phones to whisper to relatives on the land in the distant ocean, which makes the lonely sea life warmer and laughter.
Safety communication has always been an important content of maritime mobile communication. Ships sailing at sea are always faced with the danger of wind waves, reefs, shallow reefs and ship collisions. The marine telephone brings more safety to the crew.
The weather forecast at sea is an indispensable content of marine communication. Because hurricanes at sea pose the greatest threat to ships, every year in the world, ships are sunk due to hurricanes. Therefore, the coastal countries formed a maritime wireless communication network, and regularly released meteorological data of various sea areas to ships.
Marine telephones, like car phones, install wireless phones on ships and set up base stations along the coast so that radio waves can cover the coast. In order to increase the communication distance between the ship and the shore, the base station is generally installed at the highest terrain.
If the seafarer on the ship wants to make a phone call with his family, the marine telephone will transmit the radio wave to the base station and pass it through the trunk line to the land wire telephone office: the home phone can be connected through the line of the telephone office.
Ships are always loaded with a lot of cargo. When entering the customs of a country, the customs declaration is very troublesome and takes a lot of time. Now that we have a marine telephone, we can report the cargo list, crew and passenger lists on the ship to the customs one by one a few days in advance through the marine radiotelephone channel and radio terminal equipment. Of course, this is done through the data communication of the computer. When the vessel enters the port, all procedures are complete, which can save a lot of time.