Handy Submarine Formulas

[blackcan]

Good day everyone.
if this topic is in the wrong place then just move it to the right Section.

Anyway i lately wanted to createa "Cheat Sheet" a Little Notebook with all handy Information i can use in Subsim Games (it doesnt matter too much which since trigonometrie is always the same)
So if you got some handy formula i'd appreciate if you could share it with a short explaination of its purpose.

2 Formula i already have wrtten in

1) Calculcating the Mirror Contact of the Towed Array (in Dangerous waters etc.)




2) and Calculating the Course through the Periscope and "AOB"

Bearing :
<180: +180 = bx
>180; -180 = bx

bx + AOB = 0-360 (thats good) = course
bx + AOB = >360 (subtract -360) = course
bx + AOB = <360 (add 360) = course

I haven't made a Graphic for that one but it will soon
(also thanks to FPSchazly for showing that one



So everyone who got a handy formula is free to share and explain the purpose (maybe also the Era restriction (for example you don't need calculating the mirrorbearing in a WW2 Sub since they don't have a Towed Array)

Thanks in advance

Edit : if anyone knows a App in the Playstore where i can put in my own formulas and just type the Variables in would be love to know that app