Anybody know anything about the differences? I have to figure out the general area when flights from Boston and New York Area transition from Class I navigation to Class II along the eastern seaboard. Also, at what point in South American do flight transition to Class I from Class II. I know that there is no definite answer because of reroutes and the multiple flight plans available for these flights but there must be a way to figure out a box where this takes place.

All help is greatly appreciated

Illini