Passing thermal layer and DC's attack?

These are two questions:
1. Passing thermal layer makes me invinsible to passive sonar at ahead slow or with silent running? Is it working for real or it is just for show?
2. When under attack by destroyer, what is the best evasion tactic?

[NefariousKoel]

1) Yes it is in. I have noticed that some of my more distant contacts were lost after passing the layer. However, it won't make you invisible. At least, it shouldn't. Enemy destroyers should still be able to detect you, but they have to be much closer to you than normal.

[daft]

Don't know any definitive answers to any of your questions, but I usually wait until the destroyer is almost on top of me and starts speeding up for his attack run. I ring up flank speed and and give a little rudder to either side of his path (depending on the angle of his run) to get out of the kill zone. As soon as things settle down after the detonation I slow down, go to silent running and creep a little deeper depending on how close the ash cans came.

But when you are at ahead slow, what the good use of decoys?

[PeriscopeDepth]

The layer certainly causes some transmission loss, but does NOT make you invisible IRL in most cases.

PD

[daft]

Originally Posted by GakunGak

But when you are at ahead slow, what the good use of decoys?

I've never used the decoys in SH4 so I don't really know how effective they are yet.

[Dowly]

Originally Posted by GakunGak

But when you are at ahead slow, what the good use of decoys?

There´s two ways how I use the decoys. If the DD is close, I fire one up go to flank speed for a 2-3 seconds and change my depth. But if the DD is far away, like if I am leaving a port which I raided just moments ago, I fire up the decoy and continue on silent run.

Originally Posted by Henric Edwards

I've never used the decoys in SH4 so I don't really know how effective they are yet.

What I really meant was what the good use when you have to be far away from them, and when you speed up, destroyers will hear you anyway....
So, to not being heard at all is the all-stop ring?

[RedHammer]

That`s why, as previously explained, when far away, fire decoys, run silent, go deeper. Just keep away from those deadly ash can`s until those DD`s are empty of them.


S! to all

Your Friend in the Pacific

RH

So the destroyers can run out of depth charges???!!!
Oh my!!!

[HannesGM]

Yes, they run out, eventually. Either that, or the crew had their lunch break coming up

I also noticed that in SH3 - only occasionally - that the DDs seemed to run out of DCs - they'd still circle over my position, but never throw any more DCs. This was after several hours - literal hours - spent with 4 DDs overhead...

This is really good news, man, as this adds more to the realism....

[Psycluded]

The strangest thing happened to me this morning, actually. To preface, I had already dove below 250 ft in the area to find where my chief of the watch called out "passing the thermal layer", so I knew where it was, in general. My plan, as is usual, is to get within radar contact range of the convoy, so I can get a snapshot view of the formation, how they're manuvering, if at all, and the direction and speed of travel.

This time, their direction was northerly, so I submerged, sprinted north and placed myself perpendicular to their track and called an all-stop about 800m from where I knew the closest freighter would pass. I was at 250 ft, in silent running mode, watching the auto-updated map as my sonarman called in the contacts.

The first attack went perfectly. With zero forward motion, I hovered up to periscope depth when the first freighter's stern passed parallel with my bow, popped the attack scope out of the water and did a quick 360-degree scan. The closest escort was the starboard side escort (looking from the convoy's point of view) and he was astern of me at a range of about 1000 yards, off on a random search.

I lit off all 6 tubes at the juiciest targets and immediately dropped the scope back down, dove to 250 ft and moved northwest (underneath the convoy) to reposition for attack. As I was passing the first freighter (underwater mind you... he was in two pieces), I heard depth charges go off behind me, so I hit F11 and went out to look. Sure enough, that DD that was DCing where I had been, or near enough to it.

The only thing I can think of, since I'd never seen this happen in SH3 or SH4 so far, is that he must have caught me before I passed the thermocline, and that the layer in that area must have created a convergence zone, causing him to misinterpret my location.

I gotta wonder if these kinds of advanced sound behavioral characteristics are modeled in SH4. I mean, I know how to use them from playing Dangerous Waters, but if it works in SH4 as well? It would explain the gross range mis-estimations my sonarman gives me from time to time (docked ships whose range estimates put them cleanly on the beach, etc).

[JackChen]

My guess is the destroyer just came over and throw some DC's at your last known position, you know, pass the motion of I am your escort and I am doing something about your loss.

If they knew where are you are specifically, I guess they would be tracking and not throwing DC's at empty seas.

[Steeltrap]

The escorts will use the tracks of your torps to estimate your position when you fired them and attack that area fairly immediately. I'm guessing that's what you saw.

I've noticed the depth changing abilities of the subs seem to be grossly inflated. Would take well over half an hour for a US sub to get back to periscope depth from around 300' under usual circumstances (pretty sure that's what Dick O'Kane says in Wahoo).

As for being able to control your depth like that while stationary, that's just nonsense.