From my "365 Stupidest Things Ever Said™" Page-a-Day® Calendar

Great Moments in Naval Communications

U.S. ship: Please divert your course 0.5 degrees to the south to avoid a collision.
Canadian reply: Recommend you divert your course 15 degrees to the south to avoid a collision.
U.S. ship: This is the captain of a U.S Navy ship. I say again, divert your course.
Canadian reply: No. I say again, you divert YOUR course!
U.S. ship: THIS IS THE AIRCRAFT CARRIER USS CORAL SEA. WE ARE A LARGE WARSHIP OF THE U.S. NAVY. DIVERT YOUR COURSE NOW!!
Canadian reply: This is a lighthouse. Your call.

actual transcript of a radio conversation between a U.S. naval ship and Canadian authorities off the coast of Newfoundland, released by the Chief of Naval Operations on October 10, 1995 (thanks to Laura Christensen).

The rule of the sea is, man (e.g., swimmer) before man-powered (e.g., rower), man-powered before wind-powered (e.g., sailboat), wind-powered before motor... and really large ships before anything. But I really think lighthouse beats them all...