JammedStab
Consider this. You are flying a random route that is over, near, or parallel to one of the days NAT tracks. You haven't plotted your course or the NATs close to your route. All of a sudden you have some sort of emergency that requires you to descend and divert, ie engine failure. . You comply with mandated contingency procedures and now you are diverting. If you haven't plotted your route and know where you are in relation to the NATs of the day, how do you know that you are now not descending right through a NAT with a high volume of traffic? Some food for thought for those who think plotting is not needed.