[scott_c2911]

Its called leeway to let everyone know. The old sailing ships took it into account when navigating. When you plot a course the navigator sets a small amount of port or starboard rudder to compensate for it in game. If you just point your sub at heading 090 for example and say rudder amidships it will not be pointing at 090 in a few hours or so regardless of tc. This can also be attributed to the curvature of the earth modelled into the game but im not so sure about that. Sailor steve knows about plotted courses that arc across the ocean rather than a straight line but I cant remember the name for it.