Evading

[Scarredclown]

Its the second time that i attack a convoy and the escort depth charged me to hell. First time i was at periscope depth, launch my 4 torpedoes, then turn back and flee. I dive at 80 meters no result. This time i was waiting, periscope depth, silent running, i wait until they were close, about 1500 meters, launch my 4 torpedoes and i sink 3 ship ! hurray ! then i dive at 120 meters right under the convoy. I didnt have time to go very deep, i was depth charged at 40 ! What might work ? Crash diving ? isnt that to Noisy ?

[GoldenRivet]

what mods are you using?

[Pisces]

Don't take your time in going down (deep). Speed up if you have to. While flank speed might be a bit too noisy giving you away if you haven't been detected yet, medium or standard speed should get you down quicker. Diving rate is proportional to forward speed. They already know you are there if they are doing a trashcan run, so there is no need to pretend you are not there. Hurry down and then coast to a silent crawl in a clever direction. At depth you have more time to maneuver after the sound of dropping depthcharges are heard. It takes time for them to sink down to you. At periscope depth you are just a sitting duck.

I don't like to use the crashdive button. Because it forces your crew to go to a depth of 80 meters (iirc) which is a command you can't revoke. The crew still feels the need to go to that depth even when you command depth to something else. To undo it you have to go down to it. Also, 80 meters won't get you through the war. You can go deeper than testdepth with a bit of daring.

[Fahnenbohn]

Originally Posted by Pisces

At periscope depth you are just a sitting duck.

Yes.

[GoldenRivet]

Destroyers have three methods of detecting you

1. visually with the watch crew

2. passively with hydrophones - they listen for the faint sounds of your engines, props, crew activities, various pumps and motors aboard the boat etc their ability to hear these things is affected by how far away from them you are, and/or how deeply you have dived.

3. actively with ASDIC - they send out a sound pulse or ping which reflects off the hull of the submarine and tells the destroyer where and how deep you are.

avoiding passive hydrophone detection is a matter of diving deep and maintaining your distance from the destroyers and by rigging for silent running.

avoiding ASDIC detection is a matter of reducing your aspect ratio relative to the destroyer transmitting the ASDIC ping. meaning that you should keep your stern or bow pointed as directly toward the attacker as possible because...

when you are pointed AT or directly FROM the destroyer his ASDIC "sees" this target (front or back view of u-boat)

<::>

the above is easily dismissed as a school of fish or bubbles or some disturbance in the water and thus, not something to waste depth charges on just yet

When you are at a 90 Degree angle to the attacking destroyer his ASDIC sees this target (side view of the U-boat)

<:::::::::::::::>

that... is unmistakably a U-boat and obviously what the destroyer should be depth charging the crap out of

as for diving deep... there are times when i will use a higher RPM like ahead standard or even Flank to gain depth as quickly as possible, but i wont do this unless at least one of my torpedoes has already hit... otherwise the convoy will start zig zagging before i have scored a hit. dont use crash dive while submerged because this may result in a bug which causes your u-boat to slowly descend when after reaching ordered depth

another thing you can do is dive as soon as your last shot leaves the tube. make sure you are rigged for silent running - otherwise your crew will assume it is ok for them to move forward with the VERY noisy activity of reloading the tubes. Destroyers will hear reloading activities from a mile away

Use BOLD decoy canisters if available. Once the destroyer passes overhead and gives you the first run of depth charges, deploy a bold canister as he passes then turn hard left or right at flank speed. as long as you are behind the destroyer you can make as much noise as possible to put distance between you and your attacker however he will turn around to acquire you and attack you again - this means you can only hold that flank speed for maybe 10 seconds. the hope here is that when he turns about, instead of detecting and attacking your boat, he will detect and attack your decoy. this buys you time to sneak away.

finally, 80 and 120 meters is not going to do it. especially in late war, i have had destroyers pound me down to 270 meters before. If you use SH3 Commander - the crush depth is randomized every time you launch the game to a more realistic number. A Type VIIC uboat for example - depending on the historical source of information used - had a theoretical crush depth of 250-275 meters, others estimate as high as 300 meters. this differs from "Test depth" or (red line) of 180 meters because Test Depth is just the depth they took the boat to while testing the prototype.

I've had destroyers push me down to 280 meters before in my VIIC

on important note to remember... Even early in the war, when destroyers were only just trying to figure out how to beat the U-boats, the destroyers still experienced some pretty stunning successes against the kriegsmarine.

as the war progresses, and you have one destroyer sitting still listening, while others ping you - thats when it gets really tough.

GWX is designed to be as historically accurate a mod for SH3 as possible... so just be aware, you have about a 75-80% chance of being killed at some point in your commander's career. especially after 1943

refer to GWX manual pages B-17 through B-20 for more information

[ReallyDedPoet]

Check out this thread:Here

Some helpful info there

[Scarredclown]

Thx all, i'm using GWX gold. In my next career i'll go deeper ! I've evade some ping before by turning my sub in the same line as the ship that hunt me. Now its time for my third career, hoping to survive for a whole year

[UKönig]

"3. actively with ASDIC - they send out a sound pulse or ping which reflects off the hull of the submarine and tells the destroyer where and how deep you are."

Actually GR, The one thing ASDIC cannot tell the operator is how deep you are. It can reveal direction, but not depth. They too must use their intuition or instincts to bomb the right place. If you have newbie HKs, you'll have a better chance of avoiding, but if you are on the hook by experienced crews, you will have to push your boat to the limits of its depth design.
By then, it won't be the bombs that kill you, it will be pressure hull failure.

In the novel "das boot", it is described as...(paraphrased)

...The enemy has us trapped in the tendrils of his direction finder. Right now, they're turning the handwheels, searching through the 3 dimensions with pulsing beams.
The ASDIC, I remind myself, is only effective up to a speed of 13 knots. Any faster and the destroyer can no longer maintain contact. At higher speed, the ASDIC suffers interference from the ship's own noises, including its propellers, which is an advantage for us, because it allows a last moment chance to change course a little. But the enemy captain knows that we won't stand still and wait for an attack, only, which way we move is the one thing his directional boys can't tell him. Here, he has to use his own instinct.
One more break for us is that our enemy and his clever machine cannot reveal how deep we are. In this, nature is on our side. Water is not simply water. Right down to our present depth it forms layers, like sedimentary rock. The salt content and physical conditions of these layers changes constantly. And they scatter the ASDIC. All we have to do is move suddenly from a layer of warm water to a layer of cold, and the beam becomes inaccurate. Even a layer of dense plankton can influence it. And the enemy above with their apparatus cannot correct their course plotting for us, because they don't know where these dammed layers are.

But once they've found you, and are pinging your boat, being quiet is no longer part of it. Might as well make all the racket you can and go deep as fast as you can. Go silent after a series of blasts and that will help confuse them as they search the depths, actively and passively to find you again.