RFB - Avoiding detection

[Diopos]

Assuming you're in a favorable position in front of the convoy and that it doesn't change course try the "deep" approach. Under the thermal layer, possibly near "test depth" or even deeper. silent running and low speed. Monitor the situation via passive sonar. Regardless of how the game implements it, I never use active sonar (including depth-under-keel measurements) in the presence of warships.

Now the key to navigate via passive sonar is your ability to "visualize" the situation on top. Recently I was experimenting with attacking convoys from "within". This essentially meaning try to keep the "center" of the convoy at 0° relative bearing (RB) while remaining on its path.

At far distance you may have a signal with a spread of ~5-10° (centered at ~ 0° RB of course). You may have some specific "target type" resolution ie DDs (high speed screws) or merchies (low speed screws).

At medium distance the spread has widened and you can resolve flanking DDs/Escorts and probably the leading escort. Start tracking the flanking DDs and observe if there is a high speed screw signal "atop" of the low speed screws. Note if it is shifting from left to right,this indicates a leading DD doing "sweeps" in front of the convoy. Try to keep the "center" of the low speed screws at 0° RB.

At close distance flanking DDs/Escorts at 270-310°/90-50° RBs, Leading Escort somewhere at your flank or rear quadrant, low speed screws spreading from 330° to 30° RB. Your sonar man will be probably identifying closest contact at Short Range.

At this stage you'll be considering the details of ascending to periscope depth and turning to get as "vertical" as possible relative to the convoy course. But as far as the "final approach" part of your attack, you can already consider yourself IN the convoy.

At medium and close range you may need to conduct maneuvers to minimize your "aspect" relative to the DDs/Escorts.

This method works well for stock "dumb" and "straight running" convoys. But what I am trying to emphasize here is not the method itself but the "stay deep", monitor via hydrophones but above all try to "reconstruct" the situation on the surface aspect of it.

Remember that regardless of what "final approach" tactic you may choose your success will very much depend on the data you have collected during the "shadowing" of the convoy. Convoy course, speed even zig-zag patterns can be collected at this stage. Then YOU decide time, location and mode of attack. YOU have the initiative.

[Althar93]

Hi again,

Thanks a lot for your help, I put the theory into practice, and managed to intercept a convoy undetected and sink a few ships : a cruiser/carrier (I'm not too good at recognizing them ), two tankers, and hitting a passenger ship (surprised it could still move at top speed with that gaping hole in the bows).

Fortunately for me, the convoy was in a narrow line formation, with the forward scout too far ahead to see me, and the rest of the escort miles away at the rear. Following your tips, I was able to alternate between forward and aft tubes, diving underneath the convoy and following it for a good hour, surfacing every time I was ready to fire again, and using the hydrophone to make sure the rear escort was still out of reach.

Finally, I was allowed a very useless and tedious counter attack, with very inaccurate depth charging, thanks to the fact they had no idea whatsoever where I was . Thanks again !!

I just have a couple more questions you might be able to help me with :

-How do you determine whether a ping is a "found" or "search" ? For the moment, I have been relying on the intensity, and it seems to work, however I am unsure whether I can really consider myself safe if I only hear light pinging (low frequency and volume). I am asking this, because in that situation, they tend to detect me again eventually, even if I play dead. Would they still get some kind of feedback in the case of a "small" ping, explaining why they end up finding me?

-Also, when dealing with multiple destroyers, do they interact with each ,using their sensors triangulate my position, or do they simply look for me independantly ? I would have thought the first one, but they seem quite stupid at times and are not able to do anything. It is probably because I'm at the beginning of the war, but I can simply dive to 250-300 feet in my Porpoise, and have them pinging me like crazy at a distance, without being able to take an accurate shot once they go for a run...

[BillBam]

A ping means they have found you, however a light ping means they do not have a good fix and you can still evade, heavy ping "dive dive" hahaha.

They definitely work as a group. Generally one will always be listening with passive will the others ping. One part about the game that is not very realistic is that the ones listening can still hear you even when DC are exploding so you are not safe even when there is a ton of noice in the water.

[I'm goin' down]

Originally Posted by Diopos

Assuming you're in a favorable position in front of the convoy and that it doesn't change course try the "deep" approach. Under the thermal layer, possibly near "test depth" or even deeper. silent running and low speed. Monitor the situation via passive sonar. Regardless of how the game implements it, I never use active sonar (including depth-under-keel measurements) in the presence of warships.

Now the key to navigate via passive sonar is your ability to "visualize" the situation on top. Recently I was experimenting with attacking convoys from "within". This essentially meaning try to keep the "center" of the convoy at 0° relative bearing (RB) while remaining on its path.

At far distance you may have a signal with a spread of ~5-10° (centered at ~ 0° RB of course). You may have some specific "target type" resolution ie DDs (high speed screws) or merchies (low speed screws).

At medium distance the spread has widened and you can resolve flanking DDs/Escorts and probably the leading escort. Start tracking the flanking DDs and observe if there is a high speed screw signal "atop" of the low speed screws. Note if it is shifting from left to right,this indicates a leading DD doing "sweeps" in front of the convoy. Try to keep the "center" of the low speed screws at 0° RB.

At close distance flanking DDs/Escorts at 270-310°/90-50° RBs, Leading Escort somewhere at your flank or rear quadrant, low speed screws spreading from 330° to 30° RB. Your sonar man will be probably identifying closest contact at Short Range.

At this stage you'll be considering the details of ascending to periscope depth and turning to get as "vertical" as possible relative to the convoy course. But as far as the "final approach" part of your attack, you can already consider yourself IN the convoy.

At medium and close range you may need to conduct maneuvers to minimize your "aspect" relative to the DDs/Escorts.

This method works well for stock "dumb" and "straight running" convoys. But what I am trying to emphasize here is not the method itself but the "stay deep", monitor via hydrophones but above all try to "reconstruct" the situation on the surface aspect of it.

Remember that regardless of what "final approach" tactic you may choose your success will very much depend on the data you have collected during the "shadowing" of the convoy. Convoy course, speed even zig-zag patterns can be collected at this stage. Then YOU decide time, location and mode of attack. YOU have the initiative.

The above only works if the sonar man has not turned off his hearing aids!

[Diopos]

Of course you do the sonar work. No way you can do this kind of approach with "standard" sonar reports.

[Diopos]

Pings do not mean that you are detected necessarily.
An increase in ping pulses mean trouble.
Increased ping pulses with a secondary lower volume "echo-ping" means you are "fixed".

At least that is how I see it!

.

[BillBam]

Originally Posted by Diopos

Pings do not mean that toy are detected necessarily.
An increase in ping pulses mean trouble.
Increased ping pulses with a secondary lower volume "echo-ping" means you are "fixed".

At least that is how I see it!

.

It is my understanding that "in-game" you hear pings they are getting a return off you, but if it is light they do not have you good lock on you.

[Red Devil]

I too like my convoys to come to me and get into a handy position, about 20 - 30 deg off to one side, and hopefully within 2000, go down to 200 and switch off and go silent. As the lead escort is passing, normally to one side, I then order PD and later go 1/3 and begin attack. Only a couple of times have I been detected in many many convoy attacks like this.

[Admiral8Q]

Originally Posted by BillBam

It is my understanding that "in-game" you hear pings they are getting a return off you, but if it is light they do not have you good lock on you.

If the pings are getting more frequent after each one then, yes, they have you!

[Red Devil]

I think that the subject of detection should be addressed in the mods. I am going to strip game down and reinstall and start again as my detection rate has gone to 100% and I never even sneezed - must be some sort of bug?