Datum question, SH3 with GWX3

[GoDeep]

I have a question on how the AI handles the datum (the point of detection). I know that each time I stick my periscope out of the water or fire torpedoes, there is the possibility of being detected. Especially during bright daylight, calm seas, periscopes are fairly easy to spot by a veteran watch crew. Same with steam propulsion torpedoes, the wake is a give-away of the firing position.

I also know that if I am not detected and fire my torpedoes, as soon as they detonate, the AI goes into active search mode. In real life, if I have not been detected, the escorts would only have a very general idea about where I would have been at the moment I fired. They could guess this from which ship was hit by the torpedo. For instance, if a ship at the forward starboard side of a convoy was hit, the u-boat would most likely be in that area.

How is this in the game? Does the AI "know" where I fired from, or does it have to begin searching with only a very general idea of where I might be?
I ask this because even with me being very quiet (silent running, 1 knot, scope down, periscope depth, electric torpedoes so no wake), the AI seems to home in on my position very quickly. Why am I at PD? Well, there's virtually no room to dive...depth is 25 meters. (I know, stay out of shallow water!)

[Sailor Steve]

A submarine at periscope depth is easily detectable by sonar. Shallow water is one of your worst enemies.

[GoDeep]

Hey Steve,
Thanks for the reply. I know that active sonar in shallow waters is impossible to evade almost, since you can't get deep enough to get below the beam. In early war, the active sonar would be easy to avoid that way in deep water.
However, it seems to me that the escorts know too well where to search with their active sonar. They come towards me before locating me with active sonar.
Hence my question...does the AI "know" where to begin their search even if they have not detected me yet?

[Pisces]

Perhaps they do get too accurate datum information from the game. But another cause might be that you are simply too slow to evade, compared to their ability to cover their search area. It might be just a matter of time.

[Brag]

You are not silent when you launch torpedoes. The hydrophone/Asdic operator will hear a torpedo launch and know its approximate location.
Thus, it is important to get away from datum.

In well escorted convoy, it only takes an escort 3 - 4 minutes (or less) to arrive at datum.

My tactic is to go flank and dive rapidly after launch. After passing 60 meters, go silent and change heading.

[Sailor Steve]

Originally Posted by GoDeep

However, it seems to me that the escorts know too well where to search with their active sonar. They come towards me before locating me with active sonar.
Hence my question...does the AI "know" where to begin their search even if they have not detected me yet?

Good point. I like to test things with the 'Happy Times' Single Mission, and I've noticed that the DD's tend to "accidentally" follow me everywhere. They won't necessarily have my exact location, and they may be dropping their depth charges a few hundred meters off target, but if I change direction they sort of 'by chance' wander in the same direction I do.

If they hear me then at least some of them should drop right on my spot, but even if they're consistently wrong, they stay wrong in my general vicinity.

I know that's not exactly what you're talking about, but it is another questionable phenomenon.

[Jimbuna]

The escorts have a rough idea of the area you are in but that is all.

If and when they detect you they will prosecute you almost with pinpoint accuracy, depending on the skill level of the vessel/crew.

As Steve rightly states though, if they don't get that 'positive' location they will search that general area, often depthcharging as they do so.

[GoDeep]

Thank you both, that does clear up an awful lot. I can understand what Brag said, about the hydrophone operator on an escort hearing the torpedo launch. With all the compressed air rushing out, it must be a pretty noise affair. They might pick something like that up.

On the whole though, would you guys say that the AI "knows" more about your general location than would be possible in real life?

[Jimbuna]

Originally Posted by GoDeep

Thank you both, that does clear up an awful lot. I can understand what Brag said, about the hydrophone operator on an escort hearing the torpedo launch. With all the compressed air rushing out, it must be a pretty noise affair. They might pick something like that up.

On the whole though, would you guys say that the AI "knows" more about your general location than would be possible in real life?

It has always been a fine balance between historical accuracy, realism and game immersion.

Sometimes I think it is the case and other times I think not.

There are many factors the game engine needs to take into account during each encounter, weather, profile of your boat to escort, light conditions, your noise signature etc. etc.