This is how i use real navigation
Install The latest New UI mod and Trevally Automated Scripts v0.6
The navigator will give you a mark on the navigation map every 2 hours .
Make sure that your real navigation script time corresponds with the game time .

Use your compass to head in the direction you need to go . I want to head 120 degrees . To bring up the compass click on the red square in the heading bar .
In another 2 hours the navigator will give you another plot on your navigation map .

Click on your compass to change direction . I use Church's Compass Dials Mod v2.2 so the compass expands in size when i mouse over it .