Through the pitch-black night, the captain of a vessel sees a light dead ahead on a collision course with his ship.
He sends a signal: “Change your course ten degrees east. “
The light signals back: “Change yours, ten degrees west. “
Angry, the captain sends: “I’m a Navy captain! Change your course, sir!”
“I’m a seaman, second class, “comes the reply. “Change your course, sir. “
Now the captain is furious. “I’m a battleship! I’m not changing course!”
There’s one last reply. “I’m a lighthouse. Your call. “
This joke is included in the Black Book of Jokes. You can order it from here.