Originally Posted by Webster (Post 1581518)

quite simply the game "cheats" and its done on purpose and with very good reason.
if sitting on the bottom worked in the game as it does in real life then you would find it too easy to evade and elude your attackers and by default it would make the game too easy so they want you to die often and find no escape from attackers so the game stays "intense" and thrilling to you. this increases the games appeal and popularity as well as sales and this is why destroyers always know your exact position and depth from 5nm away. its been like that in all the sh games.

lets face it if the game worked as real life you could follow well established practices that make success rates very high and the game would always feel too easy and lose your interest.

Originally Posted by Catfish (Post 1581834)

Thanks for your explanation, it seems their hydrophones have a very short detection range (?)

Originally Posted by Poacher886 (Post 1582115)

"... I feel, that for the best balance between historical accuracy and gameplay, they should (like anything in war) be no right or wrong, no fixed answer to detection.

The idea that an enemy destroyer WILL detect you when moving in all but the most obvious of positions or WILL NOT detect you when performing other actions, is not the way forward.

The enemy crew down to the individual, technology, and general allertness of the crew, mixed in with weather conditions, time of day, and undersea thermals, all contribute to whether or not you will be detected in reality, the countless stories of U-boat crews strenghen this view.

For me, the most important thing is that it is 'Random' always, but odds in favour of detection or not depending on conditions / year / Your own skill. This way you carry the tension throughout the sim, never really sure whether their find you or not!!

Originally Posted by Catfish (Post 1581307)

Hello Poacher,



this is not necessarily true - thermal layers are modelled in SH5 as far as i know, but you will not know if there is any change in the water around the U-boat, be it density or thermal layers. So sometimes you will not be heard, and sometimes you will - THIS is ok in my book. Thermal layers do occur, but not everywhere, and not at the same dephts. German U-boats did not measure the water to find out layers, thermal and salinity changes. Indeed i think the US boats were the only ones to do that at that time.

From what i read you would be relative safe in anything else than absolute calm waters at periscope depth, because hydrophones will not pick you up when being slow, or even running silent at less than 100 revs per minute due to surface noise.

As well mostly ASDIC will not pick you up there as well, since the upper part of the active ASDIC detection cone is NOT parallel to the water surface. Even if it was, the wave action in anything but zero wave conditions will screw this up. It works better in shallow undisturbed waters because the sound waves are then reflected from the shallow ground, going up at an angle, and thus being able to detect the boat. But where would you find such conditions, in reality ? Even in the baltic it is almost impossible -
There is one possibility of "bent-up" sound waves, if an underwater layer is thick enough to reflect, or even bend the waves in a transition zone thus being able to detect the U-boat. Does not happen very often, and was not so well-known in the early days.

So indeed the deeper you go, the more will enemy active ASDIC/SONAR be able to detect you, BUT THERE WAS NO DEPTH DETECTION UNTIL LATE 1944. They would just detect a 2-D contact, and throw charges at varying depths to hit you by chance.


But until "capturing" the U-570 (later tested as "HMS Graph") the Allies had no idea that a german sub was able to dive deeper than 80 meters, so you would be safe until october 1941 if you go deeper than that - the depth charges would be set to 80 at most before that date. In german transmissions depth was coded as "A", meaning "Achtzig" or "Eighty". 220 meters diving depth would have been 2a+60 meters, in a coded transmission. British submarines were not able to go anywhere near a diving depth of 100+ meters, or 300 feet. This is very seldomly mentioned, even today :dead:

If there is no thermal or other density layer, blue water conditions are perfect for active ASDIC later Sonar down to 160 meters, but not near the bottom, and not at periscope depth. Below 160 meters there is again a change in sound wave transmission, making detection harder again.
Some commanders never went down that far and survived nontheless. Erich Topp says in "Fackeln über dem Atlantik" (would that be "Torches over the Atlantic"?) that he seldomly dived deeper than 30 meters, because at that depth the boat's hydrophones were perfectly able to detect and hear an attack run when it began, making an early evasion possible. An attacking escort at full speed was deaf and blind until going back to slow again - unless there is another destroyer listening. But even then this other one will not hear the boat at full speeed as long as the other D. is at its attack speed. It was not easy to detect U-boats, until late 1943 - even then you needed a well trained crew.

Using hydrophones it depends on how loud you are (obviously). If you are going slow they will not hear you in reality, as well evading depth charges by suddenly going to full speed and then decelearating again after having changed the direction, will confuse them as well.

As soon as there is more than one destroyer and they use the run and listen tactics, you will probably be toast; until you are - by chance - at another depth than the charges are set to. Without depth detection they know roughly where you are, but not how deep (In SH3-5 depth charges explode at your exact depth already in 1939).
When Walker developed his tactics of using one destroyer for listening and ASDIC, and another for the chage run few U-boats escaped, but again: Not every destroyer crew was as well trained as the U-boat hunter groups, and convoy escorts usually did not have the time and training to do that - as well the noise of a whole convoy rendered the hydrophones useless. In the middle of a convoy a boat at PD will be roughly at a depth of the surrounding freighter hulls, and impossible to detect by passive or active systems.

It is a shame that you still cannot copy the original tactics and survive after three iterations of a "developing" sim, at least until 1943.

But it looks nice. ;)

Greetings,
Catfish

Originally Posted by Webster (Post 1581518)

quite simply the game "cheats" and its done on purpose and with very good reason.

if sitting on the bottom worked in the game as it does in real life then you would find it too easy to evade and elude your attackers and by default it would make the game too easy so they want you to die often and find no escape from attackers so the game stays "intense" and thrilling to you. this increases the games appeal and popularity as well as sales and this is why destroyers always know your exact position and depth from 5nm away. its been like that in all the sh games.


lets face it if the game worked as real life you could follow well established practices that make success rates very high and the game would always feel too easy and lose your interest.

Originally Posted by silent shadow (Post 1583619)

Hi all,

I am sure I read somewhere, although I can't remember where, that asdic could detect large lumps of metal (namely U-boats) while lying on the bottom. In fact it was not unheard of for destroyers to mistake shipwrecks, in shallow waters, for U-boats and attack with depth charges.