Nightfall had come but the captain of the ship remained standing on the bridge, looking out to sea. Visibility was poor because of fog and he wanted to keep an eye out. Suddenly he saw faint lights in the distance. Immediately he called his signalman to send a message: “We are on a collision course, advise you to change your course 10 degrees south.”
Promptly a message was returned: “Advisable for you to change your course 10 degrees north.”
Startled and angry at the audacity of the reply, the captain sent a second message: “Alter your course 10 degrees south – I am the captain!”
A reply came: “Alter your course 10 degrees north – I am a seaman.”
Furious, the captain had had enough. He ordered another message be sent out: “Alter your course now, for I am a battleship.”
Back came the reply: “Alter your course now, for I am a lighthouse.”
The ship changed direction immediately.
There is much discussion of the authenticity of this story. The original version is an apparent transcript of a radio dialogue between a US naval ship and a lighthouse, released by the US Chief of Naval Operations. The office itself has denied the story as false. A popular version narrates the dialogue as between a US naval ship and Canadian authorities, another of a British ship in Irish waters.
The story has been used in motivational speeches (appears in 7 Habits of Highly Effective People by Stephen Covey) as a wisdom or religious anecdote and was made into an award-winning Swedish television advert. It is technically implausible as far as naval ships, lighthouse signalling, seafaring radio systems go but certainly has value as urban legend/parable nonetheless.