It has saved many thousands of lives, broadcast the ceasefire after two World Wars and carried countless sailors' messages back home to loved ones. But from midnight tonight Morse code moves a step closer to its demise on international fronts.
Come 1998, it will be too late for an SOS in Morse in many jurisdictions, as it will cease to be the international language of distress. Ireland, however, will be a notable exception.
If you send for help in Morse in British waters after midnight, its coastal radio stations will no longer be listening for the dots. For those in Irish waters, the code will hold good for another two years at least.
In Britain and elsewhere the 165-year-old code is being replaced by the Global Maritime Distress and Safety System (GMDSS), an automatic and usually highly accurate position-signalling system routed through satellites with built-in two-way radio.
Many of the world's major fleets have already switched to the system, which sends an SOS immediately and is not subject, as Morse is, to the vagaries of weather or sunspots, though it is understood that some seafarers are not entirely happy with the use of satellites in such circumstances.
Ireland is gradually adopting this system. But it has not yet been deployed by Irish vessels to the same extent as by many other maritime states.
Morse, nonetheless, has been on its way out for some time. The main French listening station for emergency Morse messages ceased activity last February, while the US abandoned Morse code watchkeeping on the emergency 500kHz wavelength in 1993.
Ireland seems to be the exception, as it will continue "listening" via Valentia Radio on the 500kHz emergency frequency until the end of 1999.
It is believed that over the next two years new systems for conveying emergency distress signals, most probably with an emphasis on satellite technology, will be endorsed here, coinciding with the demise of Morse. They will be heavily influenced by available technology approaching the year 2000.
The code, invented in 1832 by the American painter Samuel Morse, led directly to the development of the telegraph and has helped save many thousands of lives.
It was invaluable for ships and travellers in distress. It was also used to send out defiant radio messages from London to the French resistance during the second World War.
The code was simple, but it took Morse years of struggle to turn his "contrivance" into a working telegraph and convince the world it was worth investing in.
At one point the destitute inventor wrote to a friend: "I am crushed for want of means. My stockings all need to see my mother and my hat is hoary with age."
After 12 years, however, Morse tapped out the world's first telegram. It read simply: "What God hath wrought."
It took Marconi's invention of wireless telegraphy to open up the world to Morse code and put ships at sea in contact with the rest of the world. Since then, thousands of ships, including the Titanic in 1912, have sent out the SOS call.
Mr Mark Clark, of HM Coastguard in the UK, said: "Morse is something that has been dying out over the years. Most ships go to sea now with distress beacons which automatically send a signal to a satellite, which is a much more efficient system.
"Morse has really become a bit of an anachronism and is not relevant for today's technology."