Changing depth creates detectable noise?
 

Just a tactics question for everyone. Playing in 1968, you have to get pretty close to the enemy for your weapons to be effective whether its ASW or ASuW. This requires a lot of depth changes especially where ASuW is concerned as you have to be shallower than 100ft to use the Mk16s. Does sneaking close to a fleet at say 6-700 ft then the process of rising quickly to 90ish ft (but only at 5kts) to fire the Mk16s produce a lot of noise? Like hull popping or whatnot?

Was wondering the same, but for different reasons.

Changing depth using ballast (E/C keys) should make noise, right? If so, then how much noise exactly?

Noise from ballast is not modeled.
Only engine noise and transients.