[Onkel Neal]

Also, jima suggested: You can start a line on the chart and hold the space bar then drag that line to whatever heading you wish and it will put 0 on the protractor at whatever direction you draw the line.

Also another useful thing you can do if you want to draw a line on the chart from your sub in the direction you're heading you can start a line at the bow of your sub. Zoom in when doing this to get an accurate start point. Then type on the keypad how long you want this line to be such as 5000, then hit enter. This will draw a 5000 meter line on the chart. Then type in your heading and hit enter. This will change the direction of that line to your heading. If your heading is 0 degrees, type in 360 because it will not take just typing 0.