I have heard about a dozen versions of the following joke, with nationalities swapped around, normally with A being played by Americans/Brits and B by a cheeky small nation. Goes something like this:
A: Please divert course 15 degrees south to avoid collision
B: Please divert course 15 degrees north to avoid collision repeated several times resulting in
A: We are the Big Ship aircraft carrier group, capable of bombing nations into the stone age, fully loaded and willing to fight, YOU DIVERT COURSE
B: We are lighthouse, your call.
My question, is the joke based in any true events or is it pure fabrication?
This is simply an old joke, Snopes traced it back to 1931.