A question just occurred to me...how would this bearing theory work with the fact that we know Desmond, having returned to the freighter, called Penny on December 24th (a date which was accurate according to both freighter and island time)?
Maybe 325 is a bearing that takes you to a point where the freighter and island are at the same point in time. Maybe 305 (the bearing given to Michael) takes you slightly back in time. Am I making any sense?