Wizardess: Yea, thanks we alrady said that, no we have to expalin how someone who thinks they are going straight according to stars etc. is actually making a wide circle.
It is not something that really works, but it does happen, you can get lost in a desert and you think you are walking straight, but in reality, you will be transcribing a large circle, as one of your legs is undoubtably longer than the other.
Same thing, you think you are going straight, so when you check your instruments to confirm this (be it GPS or Sextant) you see that you are in fact going the way you want to be going.