In November 1963, I was on watch in Radio Central aboard USS Kitty Hawk CVA-63 heading v..e..r..y slowly toward Sasebo, Japan through unbelievably heavy fog. Since I'd just reported aboard and my security clearance paperwork hadn't been completed yet, I was in charge of keeping commercial press stations tuned in properly as time and longitude changed. That way, we had "up to the minute" news all the time.
Early in the morning of November 23 (Japan Time) the teletype printer for the United Press International stopped dead in the middle of an economics item. Signal was very strong and clear, just not being keyed. Then it started up again, obviously being hand-typed rather than the 100 WPM normal speed. It said:
DALLAS TEXAS. SHOTS FIRED KENNEDY MOTORCADE. MORE TO FOLLOW.
I notified the Comm Watch Officer. He knew I wasn't officially "cleared" yet, but I'd obviously read it, so he and I, for several minutes, were the only ones on the ship who knew.
History has made it "clear" that the President was shot on Nov. 22, 1963, Dallas time. For me, it's always been the 23rd, about 0400.
That's what SWL meant back in the 60s. Those teletype stations run by UPI, Associated Press and Reuters were excellent sources of hot news. Sometimes sad, but always before the newspapers got it.