Evading escorts
 

I dont want this to turn into another sh4 bash, since after having spent a few days with this sim, I think SH4 with a little bit of TLC and polishing could be a great sim and a significant improvement over SH3.

Right now, I am more interested in sinking ships. One problem I have is avoiding detection by the escorts which seem to pick me up at longer ranges than in SH3. Has anyone figured out at what range escorts pick you up? visually and on sonar.

I have found that, as in RL, you can use thermal layers to avoid detection.

For example, in the "Philippines Sea" quick mission, I dove down under the thermal layer, all ahead 1/3, passed under the escort screen, came up to PD between the escorts and the main body, pumped 6 fish in a 28,000 ton carrier, dove down under the thermal layer again and sneaked away, without being detected or attacked. Of course, I used auto TDC and cheated a bit with external view, but it matches quite well with RL attacks in WW2.

DD's are easy to avoid in my opinion, they will discover your sub in ranges like 150 meters or so if you have your periscope up, perhaps even if periscope is down and the weather is good - running silent and 2/3-speed will keep you undetected in most ranges, even close to them.

I've also noted that not extending the periscope more than neccesary (in good weather for instance) will keep you undetected as well..

2/3'rds speed and dropping below thermal layer is working really good for me!

Couple of questions:

1) What is the normal range at which you will be detected visually on the surface? I assume this is affected by the sea state and your ships heading, etc.
2) What is the depth of the layer? Is it fixed? If not, is there any way to detect it?

DD's seem ridiculously clueless to me. They lose you completely after diving below the thermal layer and silent running, and in severe cases sometimes won't even use their guns against your surfaced sub in rough weather. (this could be realism, though they dont even make an effort to move, just sit there).

There is a mod in the mods section (check the sticky list there) that makes the DD sensors improved.

2) the thermal layer changes every mission, it appears to be between 150 and 200 feet. You hear a message "passing thermal layer" when you go through. If you go at 1/3 speed and dip regularly below the thermal layer, the escorts dont pick you up, I tried again last night.

The point where the escorts pick you appear to be based on speed and distance. The first time I played the "Philippines Sea" mission, I headed at the carriers at standard speed and stayed at periscope depth. I think the escorts picked me up from fairly far away since I saw a DD heading right for me. When he was about 1,000 yds away, he started pinging at which point I ordered a hard right turn dive to 400 feet, but his first stick of depth charges got me, one way ticket to crush depth, so escorts can be deadly if you are not careful.

Right now, I am trying different speed and approaches, using and not using thermal layers to figure out when the AI picks you up.

1) visually, I get the impression the AI picks you up from farther away than in SH3, but I have not really tested it yet.

After reading your post, I decided to try that same mission. I went std. speed
at PD, right for the carriers. I passed about 7 DDs (not real close) with scope
down. I raised scope after getting near the carriers. I sent 2 torps and sank
the first one. Nothing from the DDs at all. I sank the 2nd carrier (both fleet
carriers) with 3 torps and then waited. NOTHING !! I only raised the scope
to fire, then lowered it but never left PD and never used silent running. Varied
speed between 1,2 & 3 settings. I was never in ANY danger. I did get to see
a great air show with planes bombing ships and being shot out of the sky. One
plane crashed right next to me and I thought for a moment (from the sound)
that a DD had found me !!!!! (NO SUCH LUCK)....

JIM

Unfortunately, this has NEVER worked in any of the SH4 missions I have
tried. No pings, No detection, absolutely NOTHING from the AI DDs
unless I let them see me. Then its blast a huge hole in the sea where my
scope had been....

JIM

I'm starting to think they only pick you up if you are right in front of them. I did the "Borneo" quick mission last night, did three attacks from right off the port side of the convoy, sank four freighters, was never detected or attacked by the escorts. The escorts milled around, but never got close to my position.

OK, after not having any luck getting escorts to detect & go after me,
I deceided to do something drastic. I uninstalled the game, reinstalled
it and patched to 1.1. NOW the AI DDs are actually looking for me &
have found me. I am hearing the pings now (never did before). I was
DCed and rammed and it of course SUNK me. Don't know what happened
on the first install. Something just was not right about it. BUT the game
seems to be playing like it should now after the new install...

JIM

Yeah, these reports about braindead escorts are weird. They consistently give me a hard time. I've sunk solo merchants at night only to pick up a couple of destroyers on my radar heading my way a few minutes later. I submerge and run silent and I still get depth charged to hell. That's happened several times; thinking I'd submerged and gone silent before they could've detected me.. then ping ping ping.. chugchugchugchug BOOM! :(

Retried the "Borneo" mission again last night to try out my newly acquired manual TDC skill. Followed the same attack pattern.This time, as I am lining up on a freighter, I hear sonar pings and turn around to see an escort bearing down on me, took a quick shot and dove deep. I was depthcharged for an hour before I shook off the escorts. Most of the DC's were far away, but a few were close enough to damage my desk& flak gun.

There is a real variety to the escort AI, even at stock settings.

Thats VERY strange as I also have wierd things going on, on top of the stupid DD AI.

I only seem to get one or two levels of sub creaking when submerging. I dont get the loud, metal shearing sounds when very close to my hull collapsing.

The Convoy AI seems not right either. After I hit one merchant they all seem to come to almost a complete stand still. Whereas when I engage single merchants or 2 merchants following each other, they zig zag, speed up and try to evade.

I also keep getting the same mission over and over and over (9th patrol now in Honshu, the mission marker does move, but its still the same mission).

Maybe I should try a re-install?

With the new install, I am now getting zig-zag from the TFs & Convoys.
After I torp one, they will speed up and make direction away from me.
Entirely the opposite of the first install where they would come to a
complete stop and just sit there. I don't know why all the difference
between the installs? Somehow, the first one just didn't load all the
game engine or maybe just pieces of it?? Or maybe the patch didn't
install right and messed up the game AI. With the first install, I never ran
the game on the original 1.0 version. Patched it right away....

JIM