If you really want to call this realistic you must stop hovering your sub at zero knots. Just keep 1 or 2 knots going for dynamic control. Yes it makes your precision plotting harder but you should be eyeballing AOB anyway. Speed you already know how to do with the length/time*1.94 equation. Range you have stad.
Love your videos anyway. Keep up the great work.
PS... Oh yeah! Hold down left control for fine mouse movement while using the stad!.....ur welcome.