How dangerous is to use active sonar?

[kstanb]

I am playing with TMO 2.5 +RSRD with no map update; and it is early in the war (radar is not available), so my question is:

in your experience, how dangerous is to ping a far away convoy? I am talking barely visible ships at more than 8 to 10K yards (stadimeter is useless there)

I have started to use sonar to try to figure out the convoy (or task force) course and range; and then position myself in their path; so for I haven't being spotted, and this approach has been less risky than closing (usually surfaced) to get a better stadimeter read.

thanks in advance

[tomoose]

IIRC there are previous posts asking this question. I don't think the En AI "hear" the ping but I've had a couple of incidents (in my early days) where I pinged and the escorts came a-charging. That could have been a coincidence however. If the En warship AI can't "hear" an active ping then technically it would be "cheating" if you took advantage of a game "deficiency" if you get my meaning. It's a personal choice in how you play the game.

Having said that, realism-wise, I doubt a sub skipper would actively ping if there were enemy warships anywhere around. Someone may correct me but the ONLY time I have used an active-ping is vs a solitary merchant and nothing else. Even then I rarely do it.

[kstanb]

But I read somewhere that in early war, they used sonar intensively; that they would not raise a periscope for fear of spotters, and therefore base their entire solutions on sonar; and as far as I know it is not possible to get a range without active sonar

[TorpX]

But I read somewhere that in early war, they used sonar intensively; that they would not raise a periscope for fear of spotters, and therefore base their entire solutions on sonar; and as far as I know it is not possible to get a range without active sonar

You are correct about range requiring echo-ranging; passive listening is not sufficient. Skippers were trained to make sound approaches before the war, but this tactic was abandoned almost at once. It stemmed from the results of artificial, and highly coreographed exercises where aircraft, knowing when and where to look for the approaching sub, were able to spot it. I think these tactics were predicated on using passive sonar only. AFAIK, there were no enemy ships sunk with these methods. Echo-ranging would give your presense away much faster than using the periscope, generally speaking. The periscope visibility is exagerated, IMO. The danger of having your periscope spotted is mainly confined to 1,000 yds., maybe 2,000 under ideal conditions.

In any case, I don't think echo-ranging works much beyond 5,000 yds or so. Within this distance, you should be able to obtain fair results with the stadimeter. I've never really used echo-ranging in SH 4, mainly because it was seldom used in RL. I'm sure it is possible to sink ships with sonar only (with some luck), but I think it is going about it the hard way. ;)

[Sailor Steve]

Absolutely correct. I posted this on another thread not long ago.
http://www.subsim.com/radioroom/showpost.php?p=1823481&postcount=7

[Stealhead]

Though to answer the question there is no danger in using the active sonar in game the enemy AI does not "hear" it that was the case in older TMOs I don't think it has changed my guess is that it is hard coded.Not sure with 2.5 though I have never tried it I have tested the no danger of pining in the past and it was true I did that out of curiosity though I never had an interest in trying a sound based attack seems boring to me.

They will 100% detect your radar though if an enemy ship has radar detection capabilities so keep that in mind.

You could also consider attacking on the surface at night this is very possible in TMO and you can get pretty close if you play your cards right.You can spot a TF or convoy during the day and track it until darkness by which point you'll have pretty good idea of its layout and course once you have SJ radar this task becomes much easier and you can use the radar without fear of detection until well into 1943.This depends on what class sub you are skippering with an S-boat getting into a good spot can be fairly hard thanks to the low speed in any other class it will be much easier because you can usually exceed the speed of the TF or convoy in most cases and have enough speed to change if need be.Of course all well laid plans can easily be dashed if your cat decides to jump onto your keyboard at the precise moment for the glory of the Japanese Empire.

[gi_dan2987]

I've been reading these posts and feel the urge to toss in my two cents. Real WW2 skippers would have to know the exact position of their submarine at all times on their maps in order to make accurate use of the famous 4 bearing method. Unlike in SH4, real skippers did not have the luxury of having a little submarine icon move around on their map like it does in game. So that's why sound only attacks were rare and inefficient. Sound contacts could give you an idea, but much plotting would have to be accomplished prior to the attack in order for it to properly work.

In regards to the comment about echo-ranging; I use RFB 2.0 with SH4 1.5. I will track a convoy on my surface radar until I have a good idea what their course and speed is. I then set up, wait until they're within visual distance, and begin range/bearing readings with the periscope. I make any necessary adjustment to the TDC according to the information gathered from the plots, and prepare my torps for firing.

Now here comes the part regarding preference of attack. I find that pinging for range/bearing, adjusting AOB to match course, and firing is much more fast and accurate than rifling through an ID book with my scope up in the air. Especially at night when it's hard to ID ships and see masts and funnels. I suppose real skippers would do whatever it took to gain accurate solutions. If it's dark and foggy/rainy/etc, you aren't going to be using your scope to much effect now are you?

Now here comes some questions I have for any and all to answer:

1. Regarding active sonar, can all ships (including merchants) detect when they're being pinged and begin evasive maneuver/attack?

2. Comparing apples to oranges, what is more accurate, Using stadimeter and periscope to obtain final range/bearing or using active sonar? Which one is less conspicuous? What are the advantages/disadvantages to both?

3. Concerning radar (surface and air search), from how far can the enemy detect your signals assuming they can detect them?

The reason I ask question 3 mainly is because I just completed a mission where I seemed to attract Jap convoys and task forces like flies. I fired all 24 torpedoes and racked up 30,000 tons in a hurry, but they never stopped coming. I had to run silent at test depth for most of my return trip to brisbane in my Gato class. As soon as I would surface and kick on the radar, I started attracting flies. If anyone can help me out here that would be great. Cheers! :salute:

[Stealhead]

Well number 3 in my experience the Japanese RWR is far less than the max SJ range.The last time I experimented they clearly had me pegged at around 10~12 miles sometimes less might be different in TMO 2.5 with changes and what not but I imagine it is still not near as far as the SJs max range.It seems that some AC have very good either RWR or their own radar so late war if you get an RWR hit you had better dive if it seems to be an AC. I have never had the issue you mention with radar.You might have been near a carrier TF in which case you will have encountered alot more aircraft than you would normally seem to it may have seemed like they where seeing your radar they may not have been at all depends on the year once the RWR for the sub is available you know that some IJN stuff has radar if it was pre late 43 then they generally have no RWR.

Number 2 I have not tried in TMO 2.5 but I am pretty sure that it has been said in the past that the ability for the AI to "hear" pings is 0 and that this is hard coded.So you can ping all day long they will never hear it.If they are coming after you they have you pegged in some other manner.


Attacks using just sonar all seem to have failed but they did sometimes use a ping for ranging although most crews found the SJ to be the most effective way to estimate range the real thing could actually see the splashes of deck gun shells as well as sometimes pick up low flying aircraft.Later war they also had special sonar that detected mines this sonar is not in the game.

[TorpX]

1. Regarding active sonar, can all ships (including merchants) detect when they're being pinged and begin evasive maneuver/attack?

2. Comparing apples to oranges, what is more accurate, Using stadimeter and periscope to obtain final range/bearing or using active sonar? Which one is less conspicuous? What are the advantages/disadvantages to both?

3. Concerning radar (surface and air search), from how far can the enemy detect your signals assuming they can detect them?

1. Merchant ships and the like shouldn't be able to hear you. I don't know about escorts, TBH. I always just assumed they were "listening".

2. Active sonar will be more accurate. The stadimeter requires that the mast height of the target be known. This is not always the case. Also, there are visibility issues (graphics issues) to consider.

3. I would assume that if the enemy has the capability to detect them, they could do so to the edge of the horizon ( taking the mast ht. into consideration). Remember, it is always easier to 'hear' the original signal, than it's echo. That is, when you 'ping' a ship, you must be able to hear the echo, but anyone else in the vicinity, only need be able to hear the original 'ping'. In other words, the 'ping' is always louder than the 'echo'. This applies to radar, too.

I really have no idea why you would be encountering so many ships like that. Perhaps, you got caught up in a invasion traffic pattern. Are you using the RSRDC mod?



Edit: I see Stealhead has better information. You would probably be better off to follow his advice as far as SH 4 goes.

[Bubblehead1980]

Pinging when an escort or warship is nearby , talking 0-1000 yards, just not a good idea.Otherwise, they really do not hear it unless you do it often or you are trying to ping a merchant and the warship is nearby, the ping may hit the warship and alert them.I have pinged a DD before and it got his attention, just matter of distance etc

[gi_dan2987]

The date was late 1942, early 1943 and the hunting grounds were located in the area stretching from 500nm due north of Rabaul on a line heading NW to the area between Guam and Palau islands in the west. That whole area for a radius of roughly 500-750nm was just thick with convoys and task forces. Like I said, I expended all torpedo stores and half my gun ammunition before aborting mission and returning to Brisbane in my Gato sub. I was originally supposed to drop an agent off in Tsurusaki, but obviously that didn't happen. I wasn't trying to patrol that area at all, they just kept running into me as I tried to pass through the area on the way to Japan. Obviously I had no choice but to take down as many tons as possible, and I did so with a great vengeance. By the way, I'm running RFB 2.0 over stock version 1.5.

[kstanb]

thanks a lot for your answers;

I think I will ping an escort at close range to see what happen

[MattM1121]

Well, I guess since kstanb never came back to this thread, his ping test was disastrous. :D

thanks a lot for your answers;

I think I will ping an escort at close range to see what happen

[groomsie]

But I read somewhere that in early war, they used sonar intensively; that they would not raise a periscope for fear of spotters, and therefore base their entire solutions on sonar; and as far as I know it is not possible to get a range without active sonar

Actually, this is not correct. It isn't easy to develop the range via passive sonar, but it can be done. I used this while I was in the Navy for tracking subs with a towed array, but it was developed after WW II by Lt Ekelund (story here (http://www.navy.mil/navydata/cno/n87/usw/issue_15/ekelund.html)). If you have a smart phone you can use the Ekelund range application...

Now, it is true that this was not possible in WW II without active sonar...

[groomsie]

Actually as I recall we just referred to it as TMA (target motion analysis), and we also used the technique to come up with estimated range, estimated course, and estimated speed of the target using both passive sonar (for surface and subsurface) and detection of radar emissions (for surfaced targets).

[Daniel Prates]

I think that TMA is only possible when you can correctly estimate the target's speed. Then you compare multiple bearings over a period of time, and 'fit' both data (bearings and speed) into one coherent result. If you only have the bearings, his range (and relative course too) are impossible to estimate.

So the thing is to estimate speed via some reliable source. The way I see it, the mode of choice in the last decades is TPK (turns per knot), a thing you only can use if at the same time you can also classify the target, all of that presuming you know the TPK ratio for it- a not so easy thing to do with 1940s sonar gear and intel.

[groomsie]

You would be correct for single leg TMA. To get a single solution for speed you would do multi-leg TMA.

The Eckelund method does not require any estimate of target speed, it provides range only.

I am not sure when the specific techniques I previously was familiar with were developed, but I agree they would be tough in WW II era subs.

[merc4ulfate]

I have only used active sonar to lure destroyers away from convoys. If I ping them from a 90 degree bearing then dive and go ahead flank they are more apt to center in on my last position where the ping came from while I angle in towards the body of the convoy. Imagine a T where the bottom of the letter is my position the far right point of the top cross bar is the merchants and once I pined them I headed for the top left point of the cross bar to intercept.

It really work well once in shallow water I'd say 100 feet with a rough surface. The destroyers stay in the area I pinged from while I intercepted and fired torpedoes at the merchants. By the time they turned and came back I had sank three ships and was heading away from them. They depth charged the area they thought I was in but I was a good 2000 yards away and they never approached me.

[Daniel Prates]

[QUOTE=groomsie;1879706]You would be correct for single leg TMA. To get a single solution for speed you would do multi-leg TMA.

/QUOTE]

You mean, collecting a series of bearings, then turning your own course and then collect a few more?

[twm47099]

I've been trying to learn how to use different attack methods including radar only and sonar only (active and passive and passive only).

I have a practice mission (one merchant ship, dark night) that I use. I've been pretty successful using radar only (with the OTC mod) and find that the radar range agrees closely to the chart plot ranges (with the radar and sonar only attacks, I do check once I've fired the torpedoes).

Today I tried the 4 bearing passive sonar method to get course, bearing, and target speed (3 bearings with sub stationary + one more after moving to get range.) I had the sub at 70 ft so I wouldn't get any cues besides the sonar trace which I used for the bearing measurements. I did check range with active sonar once I had a plot running, but the range was more than double the predicted (and later verified range.) So far I have not had any success with using active sonar to predict range (always over estimates.)

As the passive only attack evolved, I chickened out and decided that since the range was the most questionable thing I would use a constant bearing attack (once set up I did a second 3-bearing check on target course, but was running out of time and couldn't make the run to get a check on range)

I choose a 60 degree attack, and loaded the aim bearing, AOB, and speed into the TDC. I used the attack map which showed the sonar bearing and when the sonar trace crossed the 353 degree bearing (my aim bearing) I fired one torpedo. Once I launched I rose to P depth and raised the scope so that the ship would show up on the attack map. I had calculated the ship would be at 1600 yrds when it crossed my zero bearing, but it actually measured out to 1950 yrds. The course (and actual AOB) were accurate. The torpedo hit.

Biggest issue is that it took me a long time to collect the bearings (I used 5 minutes between bearings), and a very long time to do the graphic construction (zoom in to the chart to locate the points accurately, and zoom out to extend the lines.) Thank goodness for "pause game". I bet the WWII submariners really appreciated their pause buttons :DL And there was not enough time to recheck range.

I am surprised that my active sonar ranges are so far off.

Tom

[Rockin Robbins]

I have only used active sonar to lure destroyers away from convoys. If I ping them from a 90 degree bearing then dive and go ahead flank they are more apt to center in on my last position where the ping came from while I angle in towards the body of the convoy. Imagine a T where the bottom of the letter is my position the far right point of the top cross bar is the merchants and once I pined them I headed for the top left point of the cross bar to intercept.

It really work well once in shallow water I'd say 100 feet with a rough surface. The destroyers stay in the area I pinged from while I intercepted and fired torpedoes at the merchants. By the time they turned and came back I had sank three ships and was heading away from them. They depth charged the area they thought I was in but I was a good 2000 yards away and they never approached me.

Now THAT is a great tactic! I love it!:rock:

[ColonelSandersLite]

Wow, lotta incorrect information here. I've got a US Navy maneuvering board textbook that I found online dated 1941.

Page 26:

(copy pasted)

Case XI

TO DETERMINE COURSE, SPEED, AND RELATIVE POSITION OF A TARGET BY BEARINGS ALONE


GIVEN: TWO SETS OF THREE OR MORE TIMED BEARINGS, EACH TAKEN ON A TARGET BY AN OBSERVING
UNIT WHICH CHANGES ITS OWN KNOWN COURSE OR SPEED OR BOTH BETWEEN SETS OF
BEARINGS.
TO DETERMINE: COURSE, SPEED, AND RELATIVE POSITION OF THE TARGET.
Example.—An observing vessel G, while on course 110°, speed 15.0 knots, obtains radio bearings on target vessel Mas
follows:
Time 0800. Bearing of M 000°.
Time 0900. Bearing of M 349°.
Time 1000. Bearing of M 336°.
At 1015 the observing vessel changes course to 045° and increases speed to 20.0 knots. Bearings are next received as
follows:
Time 1030. Bearing of M 327°.
Time 1130. Bearing of M 302°.
Time 1230. Bearing of M 273°.
Required.—(a) Course and speed of M. (b) Relative position of M at 1230. (See fig. 15.)
Procedure.—Plot position of observing ship at any convenient point G, and lay out the 0800 bearing line as G . . . . bu
the 0900 bearing as G .... 62, and the 1000 bearing as G .... 63. By any of the methods shown for case IX, draw a slope
P .... Q .... R across these bearing lines so inclined that the intercepts P .... Q and Q . . . . R are proportional to the
time intervals between bearings.
In a similar manner lay out the second set of bearings, G . . . . bit G . . . . b5 , and G . . . . &6 - Draw the
slope T .... U .... V so inclined that the intercepts T . . . . U and 17 .... V are proportional to the time between
these bearings.
From any point e, lay out the first vector of G as e . . . . gu and transfer the slope P .... Q .... R to gi. Draw the
second vector of G, e . . . . g2 , and transfer the slope T . . . . U .... V to g^. This intercepts the slope from gi at zn.
e . . . . m represents the course and speed of M.
Determine the Relative Speed g2 . . . . m and by means of the Logarithmic Scale find the Relative Distance travelled
by M between the 1030 and the 1230 bearings. Lay off this distance, T . . . . W, and by completion of the parallelogram
locate the position M at 1230. T' .... M is equal to T .... W and is the Line of Relative Movement between 1030 and
1230. M's bearing and distance from G at 1230 is G .... M.
Answer.—(a) Course 164°, speed 12.6 knots, (b) 57.5 miles bearing 273° from observing vessel.
NOTE.—Solution by this method will not be obtained if the second vector of G should lie along the transferred slope P .... Q .... R.
For this reason this slope is transferred to g\ before G changes either course or speed or both.
If the bearing does not change in either set, a solution is still obtainable. The slope in this case is a constant bearing and is laid off in both
directions from the head of the vector concerned.
In case G makes a change of course when the last bearing of the first set is obtained, this bearing may be used as the first bearing of the
second set.
When bearings alone are available, the results should be considered as approximations only. This is occasioned by the fact that a small error
in one or more bearings will change the inclination of the slopes to be transferred, and this in turn will change the final results. If sufficient time
is available, a third set of bearings will act to check the course and speed of the target.

[Daniel Prates]

So Sanders, is that "multi-leg TMA"?

[ColonelSandersLite]

So Sanders, is that "multi-leg TMA"?


GIVEN: TWO SETS OF THREE OR MORE TIMED BEARINGS, EACH TAKEN ON A TARGET BY AN OBSERVING
UNIT WHICH CHANGES ITS OWN KNOWN COURSE OR SPEED OR BOTH BETWEEN SETS OF
BEARINGS.


So.. Yes. The observing ship must change course or speed or both between bearings 3 and 4.

[Daniel Prates]

:salute:

[Rockin Robbins]

I would resist any passive only TMA for the reason that it just wasn't done in WWII. I've set up a practice mission and tried it out. It works, but is just so time consuming and multi-stepped that error is almost inevitable in the game. With a fast-moving target forget it.:haha:

So you won't see me handing out passive only TMA techniques on Subsim. That being said, I use passive all the time to fire torpedoes when the target course and speed is already determined, and by superimposing the bearing on the target track I can derive the exact position. If I'm working with position keeper on, I can compare actual with projected bearing to detect target course changes.

That way I can use visual, radar, active sonar and passive sonar techniques any way I want to mix up a lethal brew of Frankenstein targeting. Usually I'm using all that with a constant bearing attack to mitigate any range errors and make setup something I can do half an hour before I shoot. I hate working under pressure. People get hurt that way.....:har:

I'm still looking for the incorrect information......... I can't seem to find it. Did someone actually utter a falsity? I just can't find a consequential misstatement, much less a "lotta."

[ColonelSandersLite]

The incorrect information:

The ability to determine a targets course range and speed from bearings alone did not exist in WWII.

That you have to be able to know your own position with certainty to do a bearing only plot.

The game tools are inadequate for the technique.

That TMA is only possible when you already know the target's course and speed.

There's too many totally different answers as far as targets being able to hear your active pings. Someone really needs to do some testing.

I also saw an assumption that merchants don't have sonar, I know of at least 2 that do (nippon and akita maru), there's probably more.

[Rockin Robbins]

The incorrect information:

The ability to determine a targets course range and speed from bearings alone did not exist in WWII.

I challenge everyone to produce a single instance of an American, British, Dutch, German, Italian or Japanese submarine doing a wartime passive sonar TMA on any target. I can't say absolutely that it didn't happen, but it didn't happen.:har: I sure hope I'm wrong but I'm not holding my breath.

That you have to be able to know your own position with certainty to do a bearing only plot.

I don't remember seeing that claim. If it's there, you're right.

The game tools are inadequate for the technique.

Now cut that out! If passive TMA is using bearings only it's fundamental that taking bearings is something our game does too well and TMA is possible. Who said that? Again, I didn't recall anyone making that argument.

That TMA is only possible when you already know the target's course and speed.

Daniel Prates said "I think that TMA is only possible when you can correctly estimate the target's speed." He did not mention course at all! And groomsie (who shares your experience in having performed TMA himself) corrected immediately that Dan's statement is true only with single leg TMA, and that double leg TMA makes estimated speed unnecessary.

There's too many totally different answers as far as targets being able to hear your active pings. Someone really needs to do some testing.

That's a possiblilty. My information that no targets respond to active sonar pings comes from Ducimus, who has torn the AI totally apart and jabbed it unmercifully to see how it yowls. If there exists any reliable source of information Duci is it.

However, I don't recall any claims to infallibility on his part. When he posted his findings I just quit pinging warships, as the results of that action would be unrealistic if Ducimus is correct. I wouldn't stake my life on it, but I have a high degree of confidence that he knows what he is talking about and is not in the habit of making unsubstantiated claims.

Let's set up a practice mission and play with it. It's been awhile since the AI was tortured and poked and it's high time we did some of that!:rock:


I also saw an assumption that merchants don't have sonar, I know of at least 2 that do (nippon and akita maru), there's probably more.

Are you talking active sonar or just passive? How can you tell? Again, I've never had any reaction from any merchant at any time of the war to being pinged. Heck, I pinged the USS Essex repeatedly when.......never mind.:88) Let's just say her reaction was to sink rapidly when I put three or four torpedoes into her. I got no subsequent chances to test Japanese merchant reactions to pings...:oops:

[Hylander_1314]

I've pinged DDs far away, and up close and personal. The only way they know I'm there, is if they hear boat noise, or spot my scope.

Not once have they charged in after pinging them. So I quit doing it, because it semed .......................................... well..................just wrong to do it.

[Rockin Robbins]

Good deal. Now some of us need to do that under more controlled conditions before we totally declare Ducimus correct. Thanks for the input.

[twm47099]

Just a question about the accuracy of active sonar in the game --
I'm using SH4 v1.5 with OTC. I find radar very accurate (tested by setting the gun range to the determined bearing and range and hitting on the first try at both long and short range.)

I find the stadimeter (Sp?) to be twitchy - sometimes slightly long, sometimes slightly short, some times accurate (as determined by the white "x" overlaying the ship in the attack map.)

But I find active sonar pings to be all over the map (except at the actual target range.) A target at 3000 yards will show a ping range of 8000 yds. A target at 2000 yards will have a ping range of 1200 yards (not consistent so I can't just say the scale is consistently off.) Bearing is very accurate, and I have run 2 leg TMA using only passive sonar and gotten accurate bearing, range, and speed. But I find pinging to only be useful for atmosphere.

Do other users find active sonar reasonably accurate? Any ideas why my active sonar is so bad?

thanks

Tom

[Hylander_1314]

Good deal. Now some of us need to do that under more controlled conditions before we totally declare Ducimus correct. Thanks for the input.

Careful there! That is almost blasphemy! :D

[magic452]

Twm47099.
To get a good active range ping you need to make sure the sonar is centered on the contact. move the bearing till the light goes off and than move the other way till the same, note the bearings and split the difference.
Lite off at 005° and lite off at 355° the target center is at zero degrees.
Once centered ping and the range should be very close.

Magic

[Rockin Robbins]

Good point there. Our sonar beam is always exactly 10º across, so you can do what you describe and get good ranges. In the real subs, sonar conditions varied. The beam might be scattered so it widened, it might be refracted by temperature or density changes in the water...let's just say that the real subs did not get anywhere near as accurate a bearing.

Where I can usually put three torpedoes of three on a target active sonar only, if I am shooting from under 1000 yards, I don't think the real sub would consistently be as accurate.

Sonar in SH4 is a long way from the truth. We are missing layers and layers of behavior from the sea itself to the adjustments on the equipment, to the separation of the different types of sonar, to filters to the complete lack of life in the ocean! Sonar is one of the worst rendered aspects of the game.

At best, we can say we get the general principles of some of the aspects of sonar. Once you get specific the real sonar guys will tear us apart!

[twm47099]

Thanks for the info. I've tried it and the ranges are much more accurate.

Today I tried another passive only attack on a lone merchant. I recorded 3 bearings at long range (at least that's what the sonar operator said) with 12 minutes between them. I used the MOBO TMA to get the course. I laid the course across the 3 bearing lines on the SH4 chart and predicted the next two 12 minute bearings. I went to flank speed on the surface about perpendicular to the predicted bearing (it was a dark and foggy night). 12 minutes later I marked the bearing from the new position while moving. The range was about 12000 yrds. I then changed course to get into position at 60 degrees to the projected course.

When the prediction said the target should be at 8000 yards, I marked its predicted position on the course line, measured and entered the bearing, estimated range and speed, and calculated AOB, and turned on the PK. I intended to shoot when the PK indicated about 0 torpedo gyro angle at 1000 yrds. At about 5000 yrds I peeked and zoomed the chart so that it showed a large plan view of the ship. The ship was less than 50yrds from the predicted track, running parallel to it. Switching to the attack map, the white "X" was touching on the far edge of the ship (port side of ship when attacking from its starboard).

I submerged and lowered the scope, and then made the attack blind waiting until the PK indicated that the torpedo gyro would be zero. I fired a 2 fish spread, first 1.5 deg forward and second at 0 offset. Then I raised the scope to see what happened. Both hit.

I realize that the probability of this happening in WWII was essentially zero, and understand that the sonar in the game is like playing with torpedo duds off (which I do - torpedo factory fantasy) for the reasons that RR explained. But it was fun. One nice thing is that I didn't use TC very much at the long range since there was a lot to do until I got the PK set up.

I'd never have a chance of getting every thing done if the target was a fast warship task force.

Tom

[Rockin Robbins]

Yes, there's a lot of confusion when there are multiple targets involved because SH4 uses only two recordings (different varieties of each for engine speed in a small number of ranges), one for generic merchie and the other for generic warship.

With a real sonar, not every target sounds the same and it is possible to locate that BB by its signature engine and propeller sounds. This is not possible in SH4 so we are left with total confusion.

Hey! Live by the simulator, die by the simulator. Some things are easier than real life, some things are harder. But it's the best we've got and I enjoy it a lot.

[Daniel Prates]

The incorrect information:

The ability to determine a targets course range and speed from bearings alone did not exist in WWII.

That you have to be able to know your own position with certainty to do a bearing only plot.

The game tools are inadequate for the technique.

That TMA is only possible when you already know the target's course and speed.


This is all true, and as far as I know, these are all unavailable techniques as far as 1940's technology goes.