Note: The following article appears in the February 2021 issue of the American Philatelist.
Introduction to Wireless Telegraphy
It all started with a dash or maybe a dot across the Atlantic. In 1901 Guglielmo Marconi, an Italian physicist, claimed to have Morsed from Cornwall across the Atlantic to Newfoundland. This event has later been rated as important as the invention of the internet or Newton’s discovery of gravity. Messages could be sent by wireless. The telegraph companies who had already laid out cables across the Atlantic must have looked with horror on their faces at the new invention that might jeopardize their monopolies. Marconi’s achievement also set the stage for a new philatelic phenomenon: ocean letters, a service for sailors and passengers onboard ships.
Guglielmo Marconi was not the inventor of wireless communication. Among others, Heinrich Hertz, Oliver Lodge, James Clerk Maxwell, Alexander Popov and J.C. Bose had shown the way, but Marconi was the one who could see the financial possibilities in wireless telegraphy. In 1897 he founded Wireless Telegraph and Signal Company Ltd. which was renamed Marconi’s Wireless Telegraph Company Ltd. three years later. This name was used for his company for decades into the 20th century. On the Figure 1 stamp Marconi is depicted with the radio device that resulted in his Nobel Prize.

Figure 1. A Vatican City stamp (Scott 978) depicting Marconi with the radio device that gave him the Nobel Prize. A similar motif appears on stamps from several countries.
Marconi’s wireless radios were installed in ships during the last decade of the 19th century. When Marconi delivered a radio, he also made the shipping company agree that his radio only could transmit to anther Marconi set, thus ensuring a monopoly for his company. He delivered and maintained the radios, paid the salaries for the radio operators whom he had trained, bought the pencils and the stationery used by the operators, provided relevant postal rates for letters, and the shipping companies paid him a fee for the service. Radios were first installed in ships crossing the English Channel, but later in navy and cargo ships. Germany, however, was not content with Marconi’s monopoly – Kaiser Wilhelm II, who had radios installed in his Kaiserliche Marine, saw to it that the two competing companies Braun/Siemens and Slaby/Arco/AEG joined forces in 1903 in a joint company Gesellschaft für drahtlose Telegraphie System Telefunken. Under Telefunken, Adolf Slaby and Georg Graf von Arco improved a radio that according to rumor was a result of industrial espionage of Marconi’s radio.
For the first time in history, the radio made it possible to know the whereabouts of ships on the high seas and to send for rescue when in distress at sea. The wreck of Titanic in 1912 sped up installation of radios on ships. In fact, the Titanic had a Marconi radio installed when it shipwrecked. Apart from military and naval use, Marconi also saw the possibilities of connecting the lonely sailors and the passengers - especially those onboard the liners crossing the Atlantic – with their loved ones at home. Early in the 20th century Marconi’s company started Morsing small “newspapers” to the big steamers – a 200 word summary of the most important news, so voyagers could keep abreast of news from home. So why not open a service for sailors and passengers to communicate home? If the Morsed message was sent from one ship to another and posted as ordinary mail from the next port of call, all the telegraph fees could be avoided and ocean letter messages sent for a fraction of the costs for telegrams. Thus, the ocean letter was a logical next use for radios.
About Ocean Letters
An ocean letter can be defined as a message Morsed from one ship to another that is on its way to a harbor. The message is written down by the receiving ship on a special piece of stationery – depending on who runs the radio and radio operator – put into a special stationery envelope or written on a piece of stationery that might be folded and sealed to look like a letter. The telegraph operator or the purser on the receiving ship takes the letters to the post office at the next port of call, has them franked and sent through the ordinary mail system. So, an ocean letter is first sent by wireless telegraph between ships and then sent as ordinary mail. Therefore German, English or French ocean letters might be franked with stamps from anywhere in the world.
Marconi was the great entrepreneur of ocean letters and radio, but Telefunken’s joint company Deutsche Betriebsgesellschaft für drahtlose Telegraphie m.b.H. (DEBEG) beat him to the finish line, offering a full ocean letter service in September 1911. A DEBEG circular was sent to radio officers on all German ships about the introduction of the new service. The telegram abbreviation was to be OZ (Ozean Brief). This was changed by an international agreement in April 1914. The telegraphic prefix became OL (Ocean Letter) and so it would remain until this day if ocean letters had not become obsolete due to modern telecommunication. DEBEG began on September 12, 1911, followed weeks later by Marconi’s Company.

Figure 2. The earliest recorded ocean letter forwarded from an unknown ship on the Hamburg—West Africa Line on arrival in Hamburg on October 29, 1911, to Krefeldt. Rate from October 1, 1907 – August 1, 1907 = 20 pfennig. Sent as first increment letter and stamps cover the printed REGISTERED, proving that you might choose to send it as ordinary letter or registered. Unless a cover includes the original message form, the identity of the originating ship is usually unknown.

Figure 3. The first type of DEBEG message form, A4 size. Messages were written by the telegraph operator who received the Morsed messages from other ships. He/she then folded it into the letter, franked it and went to the post office when the ship was moored to send the letters.
Figure 2 shows the earliest known ocean letter, sent by DEBEG. Inside this envelope was a stationery form like the one shown in Figure 3. The telegraphed/Morsed message was written on the form and put into the envelope. When the ship got into the first port of call, here Bremen, the letters were franked and sent on to their final destination. As mentioned before, you may see DEBEG envelopes franked with stamps from non-German countries, e.g. U.S., if an American port was the first post of call.
When Marconi started his ocean letter service, the procedure was more or less the same – a stationery envelope and form on which to write the message (Figure 4a). Marconi stuck to this concept until World War II.
The reverse of a Marconi message form reads:
AN OCEAN LETTER (Prefix OL) is a special class of message accepted on board ship for transmission by wireless to another vessel proceeding in the opposite direction. The latter vessel forwards the message to its destination by registered post from the first port of call.
A POSTE RADIOTELEGRAM (Prefix poste) is a special class of message accepted on board ship for transmission to another vessel proceeding in any direction. The latter vessel forwards the message to its destination through the ordinary postal channels from a selected port of call, indicated in the address.
OCEAN LETTERS and POSTE-RADIOTELEGRAMS should not be confused with ordinary wireless telegrams, which are treated telegraphically throughout.
Ocean letters could be sent at a fraction of the costs for a telegram. Fees were added to telegrams for each link they passed through. A Danish ocean letter only cost 10 øre (~ 1¢) per word, plus postage, for well over the first 20 years they existed. At first ocean letters were only sent from ship to ship, because the range for the radios was limited, but with improved radios, messages could be sent from any ship anywhere in the world to any ship that was close to a harbor of the addressee. So there was no difference in the service or the rates between ocean letters and Poste Radiotelegrams. Collectors call both ocean letters in spite of the prefix on the message form.
For the first years of ocean letters, the sender might choose between ordinary rate or registered. The telegraph operator was in fact functioning like a postmaster and was equipped with postal rate tables to make sure franking was correct. Most were sent as registered until 1925, probably because senders wanted to make sure they reached the addressee, considering the sender had already paid a higher price than for an ordinary letter. Around 1925 the service seemed to be so reliable that registration was abandoned in most cases. Most ocean letters were sent as first class mail. Of course, you might send them as express letters or “special delivery,” as it was called in the U.S., if you paid the proper fee for this service.

Figure 4a. The first type of message form used by Marconi’s English company.

Figure 4b. An ocean letter from an unknown ship forwarded on March 25, 1920, in Jamaica. Local rate from July 1, 1919 – June 1, 1921 = 1½ d. Registration fee from January 1, 1906 – June 16, 1921 = 2d. Total 3½ d. Franked with two War Tax stamps. Part of the rate was a tax for restoring the economy of the country after WWI.
Collectors of ocean letters look for stationery envelopes with the original form enclosed, and of course ocean letters franked with stamps from less usual destinations. For example, the Figure 4b letter has Jamaica stamps that even show War Taxing.
The Big Players – Marconi and DEBEG

Figure 5. An ocean letter forwarded from an unknown ship February 9, 1933, in New York, sent to the incoming president of the U.S. With printer’s imprint “S.34” in bottom left corner. Rubber stamp: Marconi’s subsidiary office address in case of return. Foreign rate from May 14, 1923 – May 1, 1940= 2½d.
Marconi bought several companies and established subsidiary companies in several countries, which over the decades were consolidated, served different purposes, and were frequently renamed. For example, ocean letters can be found from the Marconi company British Wireless Marine Service, established in 1928, and from subsidiary companies in Norway and Italy. He also had radios installed in four Danish ships. It requires specialist knowledge to distinguish the different printings of Marconi stationery, with at least 29 different prints recorded. The new company’s stationery from 1928 onwards looks very much like the old company’s (Figure 5). Notice that this one was addressed to the U.S. president Franklin Roosevelt.
Germany’s DEBEG company was not as consistent when it came to the design of its ocean letters and forms. In 1925 the red envelopes were scrapped and a new design in blue and white was introduced. The rather boring grey form was replaced by a smaller one also in blue and white (Figure 6). The envelopes had small changes in the design but stuck to the same colors until the end. There are at least five red types and 13 blue ones.

Figure 6. DEBEG’s new message form design from 1925, which they kept with small changes until the end.

Figure 7. Ocean letter forwarded October 19, 1932, by airmail from Port Sudan to Atbara and from Brindisi as surface mail to Germany. The airmail label was crossed out (known as a Jusqu’à mark) in Brindisi. This indicates that the letter continued from Brindisi by surface mail. Domestic rate from May 14, 1923 – May 1, 1940 = 2½d. Airmail rate = 2d. Total 4½d. Ocean letters from outside of Europe or North America are rarely seen.
One of my favorites is the example in Figure 7, a German ocean letter in the new 1925 design, sent as airmail from Sudan – a rare combination. The Germans had a sailing route east of Africa, and after posting in Port Sudan it was transported to Atbara for airmail transportation to Brindisi and then by train to Germany.
The Germans were quite innovative when it came to speedy communication. One of their innovations should be mentioned here. Two German vessels SS Bremen and SS Europa had a device installed when they were launched in 1928 that could launch an aeroplane when they were within flying distance of Europe or the United States. This sort of catapult mail could shorten delivery by a couple of days. Figure 8 is an example of a catapult letter, first Morsed to the ship and then flown ashore (Figure 9) and mailed. The two vessels had their own post offices onboard and therefore the cover was franked and stamped onboard before flying to Southampton, and then onwards to Bremen, Germany. Speedy communication was top priority.

Figure 8. A catapult ocean letter forwarded from SS Europa June 21, 1933, from Southampton to Berlin, June 22, 1933. Domestic rate from May 1, 1933 – March 15, 1935 = 25 Rpf. Catapult surcharge = 50 Rpf. Total 75 Rpf. Catapult ocean letters are quite elusive.

Figure 9. The Heinkel HE 12, a German mailplane built to be launched via catapult, on the SS Bremen, 1929.
Suppose you were sailing across the Atlantic and there were no vessels you could Morse to in the vicinity. But instead, maybe there was a Zeppelin! Three such ocean letters with message forms are known, all of the DEBEG type. The Zeppelins did not have ocean letter stationery, so they typed “ocean letter” (ozeanbrief) on the front and used their own stationery envelopes and forms. Figure 10 is such a letter Morsed from the ocean liner SS Roland to Graf Zeppelin on its flight from South America to Friedrichshafen, Germany, where the letter was mailed on arrival.


Figure 10a and b. An ocean letter with contents sent from SS Roland, forwarded from Graf Zeppelin in Friedrichshafen, October 19, 1932. Canceled with Graf Zeppelin, with a Friedrichshafen machine cancel on the back. Domestic Zeppelin airmail rate from June 7, 1932 – May 11, 1934 = 150 Rpf. The earliest recorded Zeppelin ocean letter out of three, with contents.
DEBEG established a subsidiary company in the U.S. around 1925, run by a gentleman called Boehme whose name is printed on the back of the American ocean letters from DEBEG. These look like the German ones, but as seen on Figure 11, they were preprinted with “special delivery” on the front and Boehme and a U.S. address on the back. So, this letter was delivered right away to the addressee when it reached its last post office, and did not await normal delivery. The fee for this service was paid by the “special delivery” stamp next to the ordinary stamp. Usually the ships only had stamps for sale from their countries of origin, so if “special service” was requested, the telegraph operator could not just put the letters in the ship’s mailbag, but had to go to the nearest post office at the next port of call and pay in cash for the service as fees are usually only accepted in local currency/stamps.

Figure 11. An ocean letter forwarded from Alber Ballin June 15, 1926, in New York. Boehme design (the DEBEG branch in the U.S.), printed in November 1925. Notice the Special Delivery preprint. Domestic rate from July 1, 1919 – July 6, 1932 = 2¢. Special delivery fee from October 1, 1885 – November 1, 1944 = 10¢. Delivered immediately to addressee on arrival at G.P.O., New York, by special messenger.
In rare cases this can result in a cover with stamps from two countries. Figure 12 shows an English Marconi ocean letter with an English stamp, paying for ordinary mail, and a special delivery stamp. Mail from a ship can be franked with the stamps from the ship’s home country for ordinary delivery like paquebot letters, but English stamps are not valid payment for a “special delivery” fee. A faint red “Fee claimed by office of first address” handstamp on the envelope indicates that the special delivery fee was credited to the post office of the delivery address, even if the letter needed to be forwarded.

Figure 12. A Marconi envelope forwarded from an unknown ship in New York, August 6, 1935, with the British stamp obliterated with a New York paquebot postmark and the special delivery stamp canceled with a New Your G.P.O. duplex handstamp.. British empire rate from May 14, 1923 – May 1, 1940 = 1½d. Special delivery fee from October 1, 1885 – November 1, 1944 = 10¢. Special delivery stamp affixed at post office on arrival in New York. One of two recorded two-country-franked ocean letters.
Here ends Part 1 of "Ocean Letters." Part 2, coming soon, will introduce readers to the wide range of ocean letters sent by companies besides Marconi and DEBEG, and cover the final days of the service as technology advanced past it.
References
This article draws almost entirely from my own research, which is available in part (a catalog of Marconi’s and Danish ocean letters) at http://www.tpo-seapost.org.uk/tpo2/spocean_catalog.html. Roger Hosking’s introduction to ocean letters, an important and early resource, is also available on www.tpo-seapost.org.uk.
Hosking, Roger. “An Introduction to Ocean Letters” (TPO & Seapost Society, 2002). “Ocean Letters - a Sequel” (TPO & Seapost Society, 2005).
Articles from Posthistorisk Tidsskrift (Danish Postal History Society) (No. 3, 4 – 2007) (No. 1-4 – 2008) (No. 2 - 2018).
Frick, Richard. Schiffspost im Nordseeraum (Hans Grobe, Hannover; 1981).
Articles from Deutsche Briefmarken-Zeitung (DBZ) (March, April, May, and July 2014).
Det Danske Post- og Telegrafvæsen. Beretning om Virksomheden 1917-67, vol 1-3.
Hancock, H. E. Wireless at Sea, The First Fifty Years (Marconi Marine; 1950).
Johnsen, A. O. En innsats i radioteknikkens tjeneste, Norsk Marconiselskab 1919-1949 (Johansen; 1949)
Jacobsen, Kurt. Fra prikker og streger til tele-og datakommunikation, Store Nordiske 125 (GN Store nord; 1995)
Wedervang, B. De danske kyststationer 1904-2010 (Post og Tele; 2011).
Larsen, S. B. 75 år på bølgelængde (Radio-telegrafistforeningen; 1992).
Knudsen, E. K. Lyngby Radio oxz – fra eventyr til saga blot (2012).
Thorsoe, Soren, et. al. DFDS 1866-1991 Ship development through 125 years (World Ship Society/DFDS 1991).
Instruks for Radiostationer i skibe eller luftfartøjer (from 1919-1980).
Gerald C. Skibsradioens historie i Danmark (Lundgren & Andersen; 1963).y
Bangay, R. D. The Elementary Principles of Wireless Telegraphy (London: The Wireless Press; 1916).
Buchmann, F. A. 50 jahre DEBEG 1911-1961 (Berlin: Behrens Hbg; 1961).
Graa, P. Hundrede år på havet 1866-1966 (DFDS; 1966).
Krüger, Reinhard. Radiotelegramme, Oceanbriefe und das Ende der Seefunktelegraphie im 1. WK (Morgana; 2017).
The Author
Otto is a retired senior master from the University of Aarhus, Denmark, with degrees in English, Art & Design and Counselling. He has collected and exhibited Greenland Postal History (international gold), ocean letters, and some local Danish exhibits. Otto has published several books especially on postal history and countless articles in stamp magazines and on the net. He is presently the editor of the magazine for Danish Postal History. He has received several awards including Danmark Medaljen, the highest award in Denmark for philately, and is an honorary member of Danish Postal History Society.
For Further Reading
Recommendations from the APRL research staff:
“Ocean Letters and Their Predecessors,” P.S.: A Quarterly Journal of Postal History 15(3), 1993 3Q.
An Introduction to Ocean Letters. Hosking, Roger (Surrey: T.P.O. & Seapost Society, 2002). IP69908
Ocean Letters: A Sequel. Hosking, Roger. (Surrey: Roger Hosking, 2005). IP69909