You bet. I found that 1 degree markings were crucial - especially with the new addition of the "make course to what degree the periscope is aiming", since the compass lacks a major sort of precise ability. You'll find the mod for the 1 degree markings for the periscopes here:
http://www.charliex.com/sh3/. Also, remember that you can hold down the Ctrl key, and move your mouse left or right and it'll move the scope VERY slowly as opposed to hitting and holding Shift, as it will move the scope very quickly.
Good hunting!