Ocean-going seaman of this era were often called "blue jackets", or "jackies" for short, based on their traditional uniform. Although not identified in this article, the "Washington" radio station responsible for the nightly news broadcasts was most likely NAA, located in nearby Arlington, Virginia. These transmissions were in Morse code.
Popular Mechanics, September, 1918, page 336:
JACKIES GET NEWS DAILY BY WIRELESS
By "broadcasting" wireless messages from Washington each night, the government has abolished the isolation which the crews on its fighting ships, along with those on all other vessels, have suffered from while at sea. Now each day's news is carefully sifted and condensed into 800 to 1,000 words which are ticked off at Washington on a wireless machine, operated by a perforated ribbon previously prepared for the purpose. By broadcasting is meant the sending of messages so that any vessel, battleship, or merchantman, with a properly tuned instrument, can receive it. The news items, which always aim to cover a wide field of interest, are relayed from Atlantic-coast stations for the benefit of the more distant vessels.