What this mod is in essence...
1) It's pure Trigonometry, no mapping or plotting
2) From a 1 degree measurement (this can be up/down scaled when popping the scope up or down, depending on circumstances), you can effectively calculate within seconds, via swinging a 'slide rule':-
a) Relative target course (this is normal)
b) Target Range
c) Target Range at torpedo impact
d) Target speed
What more do you want to know...
