I spent an hour looking through my past posts....going back to 2007, and couldn't find a specific post regarding the issue of the one degree difference in heading when turning port or starboard.....
but, I know it's a "known" issue. Could be a post regarding this one degree error in one of the pages of RFB. I know there were map images of the one degree inaccuracy included in the posts....I just couldn't find it.
However, I
do remember this is a problem with the stock game while using the map bearing compass. As memory serves me, you will start out with the sub traveling at zero degrees when first applying power, but as you turn left or right, the bearing compass will show one degree off center.
The 3000 yard bearing compass is accurate. As I remember, the game's idea of what is exactly 360 degrees is at error. The game can't quite register that zero and 360 degrees are the same.....(silly computers) it just doesn't "compute" Spock, its illogical!! That's probably why the stock game didn't give us a map compass bearing.....the dev's knew the logic of the computer wouldn't allow for the bearing compass to accurately show on the map.
So, there's not much we can do about it. I remember off-setting the bearing compass by one degree to compensate for the turning error....it just made the other direction of the turn error by two degrees, instead of one.