How to send a message (telex) to a ship on the high seas

For example, you want to wish your friend Roman a happy birthday, and he is fishing. You do not know the numbers of the terminal installed on his yacht , but here the INMARSAT directory will help us out- it has all the ships equipped with telex terminals (Russian names must be written in transliteration). Many things were found, but we are interested in the number after which it says [Inmarsat C Text / Data]. It remains to figure out which of the 4 INMARSAT prefixes to indicate before the number. If the navigation area is known, then 581 should be used for the East Atlantic, 584 for the West, 582 for the Pacific, and 583 for the Indian. If the region is unknown, you can iterate over all 4 prefixes sequentially - one of the messages will definitely reach, but money will not be charged for undelivered messages (more precisely, they will be returned to your account after an unsuccessful attempt).

www.napishi.ru/telex.asp