PLotting from the periscope

[Nuoz]

Hello everyone. I need some help. I want to know how do you plot from the periscope. I'm playing GWX 2.0 with OLC and nothing else cept for Sub Command. I find it rather hard to plot from the scope if i don't have a range before hand. Can you post some examples? What i tried to do was getting within 4.5 kilometers from target and use the range and AOB finder, which i do. The problem is plotting this information in the map. Think i have troubles getting the true bearing and i'm taking too long. I just need one range though. One very accurate range. Share ur method!

[Abd_von_Mumit]

This methods are sufficiently described in OLC GUI video manual (you've allready got it probably), as well as in very good manuals:
- Kriegsmarine Angriffscheibe Handbuch (in English) by klh,
- U-jagd tools mod manual by joegrundman.
I firmly believe you won't need more support if you read and learn the methods they desribe.

U-Jagd tools included in OLC GUI mod let you get the range very easily, FAST and accurately, especially when submerged. With some practise (it took me several patrols) you get the range with just a glance. Marvellous!

[Nuoz]

Also the AOB is really fast! It's awsome. And thinking we aren't cheating, it's actually how it was done. Great challenge = great fun

[joegrundman]

Don't forget once you have AOB, if you want it you can convert easily to target course using the attack disk. Using this method and one range reading is more accurate than depending only on two range and bearing readings.

OF course if possible you should do it multiple times - you can never have too good a solution

BTW You can also use the attack disk to convert from relative bearing to true bearing

[Pisces]

I don't quite understand what you mean with 'to plot from the scope', especially if you (feel you) need to know a range before using the range/AOB finder. That's the first thing you get from it!

Whether you use OLC gui or not, this is required reading you you plan to do manual targeting (and the links in the first message):

http://www.subsim.com/radioroom/showthread.php?t=90234

Lately I've been relying on my watch officer (too much) to give range and relative bearing. I find it difficult to get long-range measures. And the bearing scale on the scope is too crude for my liking.

To get true bearing you can use the attack-disk like Joegrundman said, it doesn't get any simpler and quicker than that. But otherwise, if you want to calculate it mentally, just take your time an take it easy. Rushing yourself is the prime cause of errors. It is sometimes neccessary so make sure you need to as little as possible. The trick is to be prepared and memorize as little data as possible.

Plotting process

Prepare:

- by zooming in to your general uboot area. The zoom level depends on how easy you do the following steps, and how fast you are moving with your uboot. Zooming/panning takes time.
- make sure the target is identified before taking the sighting. It only needs to be done once.
- If you want to plot relative bearings directly on the map you need to place a protractor (double-line-angle-thingy) before hand. One leg neatly along the uboot's course. The corner of it near or on the uboot position. But the uboot mark probably moves away from it. No worries, you'll move it correctly later at the right tiime. The other free leg anywhere, but prefferably near the (guessed) general target location.
- while identifying the target also determine if the target is moving away or towards you. For me it takes time to see it clearly, that takes longer than I want to do during the true sighting. Also, this doesn't change (very often) between multiple plots.

Doing the sighting:

When you look through the (attack)scope at the moment to get range and bearing, just look only at the height and halve-width (bow left or right?) marks of the target and write them down. Then unlock the scope if you had it locked while looking (and very important) and don't move it anymore Lower the scope below the water (to avoid detection). Start the clock (assuming you want to get speed based on later map plots). Don't worry about setting the Range/AOBfinder wheels yet. You don't have to memorize anything yet because the AOB and range data are now 'stored' on your piece of paper, and the target bearing is 'stored' in the way the periscope is oriented (which you can read anytime later you want, so that's the reason you shouldn't move it!) First thing you want to do ask quickly as possible once you have done the sighting is to mark the current position of your uboot on the map. Zoom in as close as possible to your uboot and correctly place the corner of the protractor at where the uboot is (or start a new line or circle there if you did the true bearing calculation in your head or on attack-disk). Line distance or direction is not neccesary. You just want to mark the location of the uboot as quickly as possible on the map.

Do the above as quick and smooth as possible. Without stressing yourself!

Done? Yes? Now you can take it easy. But you don't have time for a cup of tea, though. Time to get them (AOBfinder) 'wheels' rolling! In plenty of ease.

Go to the (attack)scope and read of (relative)bearing. Write that down on paper aswell just for safe keeping, together with the height and width.

Pull down the Range/AOB finder. And set up the range calculation based on the heightmarks. I understand from your words that you understand those steps. If not, study the video or Friedl9te's walkthrough mentioned in OLC Gui thread.. Read of range from the range scale. Remember the wheel gives it in hundred meters, so 22 is 2.2km, 100=10km. Then, you guessed it ... write it down also!

Followup with AOB calculation. 'Left bow' width-marks means left or port AOB, 'right bow' width-marks means right or starboard AOB. A target moving away has an AOB that is greater than 90degrees, which the AOBfinder cannot calculate. Subtract the calculated AOB from 180 to get true AOB in those cases. AOB is not really neccessary for plotting (multiple position plots give you course for free) but it is good to know to get a quick idea on target motion at the first plot. So you might aswell calculate it. You can draw it on the map in a short while. Besides, now you have all the time to do it. Well, that maybe a bit of an overstatement. ... But write it down!

All your information is now on paper, and one bit on the map (uboot location at the time of sighting). Only you don't have speed. That requires a second plot on the map after a reasonable amount of time (think minutes, not seconds like in the stock SH3 'notepad way'). Or by the speedmeasurement timing the bow-to-stern passage in the scope. But that should be done when you're not doing plotting anymore, as you need the stopwatch and turn the scope for that.

Go to the map:

True bearing to target calculation (in your head and on the map):
If the relative bearing is on the starboardside (right,0-180), just move the free protractor leg until the angle shows on the corner number. No mental math neccessary. You have just drawn the true bearing because the uboot course was allready laid in during the preparation phase. If the relative bearing is on the portside (left, 180-360) the number on the corner should be made (360-bearing). This is the only time you have to do it in your head. Draw a line/circle along the 'bearing leg' starting from the uboot to set the range.

If you did get true bearing using the attackdisk: Take the free endpoint of the line (not protractor, it doesn't show lenght) starting from the (now past it) uboot position and move it while looking at the 'reverse compass' scale around your cursor(180 at the top). It may seem as if it is wrong but it isn't. If you need to plot 180 degree true bearing the line startpoint should be above the cursor. So the line passes through the 180 mark. It's simple once you see it.

At the same time you try to aim the cursor in the right direction look at the range number on the line/circle startpoint. That should be set to the range number you wrote down earlier.

First position plot is done!

If the line length (or circle radius) and direction is correct you have made your first position plot of the target. A couple more after some time inbetween (again, minutes not seconds) and you can measure the distance between those point to tell the target speed. A good time in between sightings is 3minutes 15seconds, because the 'hundred meter' number tells the amount of knots (in other words: 1.1km in 3m15s is 11 knots). I personally find this a good first approximation. But not enough to enter into the TDC. I measure the distance (and course) over 32 minutes 24 seconds, then 11km is 11.0 knots. But I use a real stopwatch for that, not the ingame chronometer. Also consider the fact that the endpoint of the line (or tip of the circle radius arrow) is not the 'exact' position of the target. It is only as good as your sharp eye alowed to to see those marks in the scope. And the further they are, the less they 'grow in size'. Also, at best you can get bearings in 1 degree, and that is 175m wide at 10km distance, 280m at max visual distance of 16km. You're simple never going to be as precise as your Watch Officer (100m steps in range upto 16km, but still 1 degree wide).

Plot the AOB on the map: Place a protractor on the bearing line to the target. The first point somewhere along the line, best nearer the uboot side. Put the corner on the position of the target plot. Place the last leg of the protractor on the left or right side of the bearing line, the same as left(port) or right(starb.) AOB. The length of the last leg is of no importance, the direction ofcourse is. The number in the corner should reflect the AOB.

Now the plotting of the target's position and course is done. You can repeat the whole process by taking a sighting and doing all the rest to refine target course and speed as neccessary. If you want you can speedup/change course to better keep up with your target and avoid detection. Or get in the propper position to fire. Whatever the situation demands.

It sounds like a whole lot that I described here. Just consider I am a man of many words (well side-thoughts mostly ) It looks more than it really is. Print it out if you need, and read during the pausing of your game during practise. The most important part is to do the sighting and uboot mark plot in one quick sequence. And worry about the rest later. There is plenty of time available in naval warfare.

[Nuoz]

Originally Posted by joegrundman

Don't forget once you have AOB, if you want it you can convert easily to target course using the attack disk. Using this method and one range reading is more accurate than depending only on two range and bearing readings.

OF course if possible you should do it multiple times - you can never have too good a solution

BTW You can also use the attack disk to convert from relative bearing to true bearing

Very true. But it takes longer and i want to have this mental calculus ready, it's always good. In the OLC video guide he starts by using the watch officer to get a range and relative bearing and quickly he says "301 bearing, that's 57 bearing relative to my course", which was 182 by the way. The way i figured he reaches this figure is by subtracting 301 from 360 (north, 000) but this should and i think it is called "bearing to the north as well.

[Nuoz]

Originally Posted by Pisces

I don't quite understand what you mean with 'to plot from the scope', especially if you (feel you) need to know a range before using the range/AOB finder. That's the first thing you get from it!

Whether you use OLC gui or not, this is required reading you you plan to do manual targeting (and the links in the first message):

http://www.subsim.com/radioroom/showthread.php?t=90234

Lately I've been relying on my watch officer (too much) to give range and relative bearing. I find it difficult to get long-range measures. And the bearing scale on the scope is too crude for my liking.

To get true bearing you can use the attack-disk like Joegrundman said, it doesn't get any simpler and quicker than that. But otherwise, if you want to calculate it mentally, just take your time an take it easy. Rushing yourself is the prime cause of errors. It is sometimes neccessary so make sure you need to as little as possible. The trick is to be prepared and memorize as little data as possible.

Plotting process

Prepare:

- by zooming in to your general uboot area. The zoom level depends on how easy you do the following steps, and how fast you are moving with your uboot. Zooming/panning takes time.
- make sure the target is identified before taking the sighting. It only needs to be done once.
- If you want to plot relative bearings directly on the map you need to place a protractor (double-line-angle-thingy) before hand. One leg neatly along the uboot's course. The corner of it near or on the uboot position. But the uboot mark probably moves away from it. No worries, you'll move it correctly later at the right tiime. The other free leg anywhere, but prefferably near the (guessed) general target location.
- while identifying the target also determine if the target is moving away or towards you. For me it takes time to see it clearly, that takes longer than I want to do during the true sighting. Also, this doesn't change (very often) between multiple plots.

Doing the sighting:

When you look through the (attack)scope at the moment to get range and bearing, just look only at the height and halve-width (bow left or right?) marks of the target and write them down. Then unlock the scope if you had it locked while looking (and very important) and don't move it anymore Lower the scope below the water (to avoid detection). Start the clock (assuming you want to get speed based on later map plots). Don't worry about setting the Range/AOBfinder wheels yet. You don't have to memorize anything yet because the AOB and range data are now 'stored' on your piece of paper, and the target bearing is 'stored' in the way the periscope is oriented (which you can read anytime later you want, so that's the reason you shouldn't move it!) First thing you want to do ask quickly as possible once you have done the sighting is to mark the current position of your uboot on the map. Zoom in as close as possible to your uboot and correctly place the corner of the protractor at where the uboot is (or start a new line or circle there if you did the true bearing calculation in your head or on attack-disk). Line distance or direction is not neccesary. You just want to mark the location of the uboot as quickly as possible on the map.

Do the above as quick and smooth as possible. Without stressing yourself!

Done? Yes? Now you can take it easy. But you don't have time for a cup of tea, though. Time to get them (AOBfinder) 'wheels' rolling! In plenty of ease.

Go to the (attack)scope and read of (relative)bearing. Write that down on paper aswell just for safe keeping, together with the height and width.

Pull down the Range/AOB finder. And set up the range calculation based on the heightmarks. I understand from your words that you understand those steps. If not, study the video or Friedl9te's walkthrough mentioned in OLC Gui thread.. Read of range from the range scale. Remember the wheel gives it in hundred meters, so 22 is 2.2km, 100=10km. Then, you guessed it ... write it down also!

Followup with AOB calculation. 'Left bow' width-marks means left or port AOB, 'right bow' width-marks means right or starboard AOB. A target moving away has an AOB that is greater than 90degrees, which the AOBfinder cannot calculate. Subtract the calculated AOB from 180 to get true AOB in those cases. AOB is not really neccessary for plotting (multiple position plots give you course for free) but it is good to know to get a quick idea on target motion at the first plot. So you might aswell calculate it. You can draw it on the map in a short while. Besides, now you have all the time to do it. Well, that maybe a bit of an overstatement. ... But write it down!

All your information is now on paper, and one bit on the map (uboot location at the time of sighting). Only you don't have speed. That requires a second plot on the map after a reasonable amount of time (think minutes, not seconds like in the stock SH3 'notepad way'). Or by the speedmeasurement timing the bow-to-stern passage in the scope. But that should be done when you're not doing plotting anymore, as you need the stopwatch and turn the scope for that.

Go to the map:

True bearing to target calculation (in your head and on the map):
If the relative bearing is on the starboardside (right,0-180), just move the free protractor leg until the angle shows on the corner number. No mental math neccessary. You have just drawn the true bearing because the uboot course was allready laid in during the preparation phase. If the relative bearing is on the portside (left, 180-360) the number on the corner should be made (360-bearing). This is the only time you have to do it in your head. Draw a line/circle along the 'bearing leg' starting from the uboot to set the range.

If you did get true bearing using the attackdisk: Take the free endpoint of the line (not protractor, it doesn't show lenght) starting from the (now past it) uboot position and move it while looking at the 'reverse compass' scale around your cursor(180 at the top). It may seem as if it is wrong but it isn't. If you need to plot 180 degree true bearing the line startpoint should be above the cursor. So the line passes through the 180 mark. It's simple once you see it.

At the same time you try to aim the cursor in the right direction look at the range number on the line/circle startpoint. That should be set to the range number you wrote down earlier.

First position plot is done!

If the line length (or circle radius) and direction is correct you have made your first position plot of the target. A couple more after some time inbetween (again, minutes not seconds) and you can measure the distance between those point to tell the target speed. A good time in between sightings is 3minutes 15seconds, because the 'hundred meter' number tells the amount of knots (in other words: 1.1km in 3m15s is 11 knots). I personally find this a good first approximation. But not enough to enter into the TDC. I measure the distance (and course) over 32 minutes 24 seconds, then 11km is 11.0 knots. But I use a real stopwatch for that, not the ingame chronometer. Also consider the fact that the endpoint of the line (or tip of the circle radius arrow) is not the 'exact' position of the target. It is only as good as your sharp eye alowed to to see those marks in the scope. And the further they are, the less they 'grow in size'. Also, at best you can get bearings in 1 degree, and that is 175m wide at 10km distance, 280m at max visual distance of 16km. You're simple never going to be as precise as your Watch Officer (100m steps in range upto 16km, but still 1 degree wide).

Plot the AOB on the map: Place a protractor on the bearing line to the target. The first point somewhere along the line, best nearer the uboot side. Put the corner on the position of the target plot. Place the last leg of the protractor on the left or right side of the bearing line, the same as left(port) or right(starb.) AOB. The length of the last leg is of no importance, the direction ofcourse is. The number in the corner should reflect the AOB.

Now the plotting of the target's position and course is done. You can repeat the whole process by taking a sighting and doing all the rest to refine target course and speed as neccessary. If you want you can speedup/change course to better keep up with your target and avoid detection. Or get in the propper position to fire. Whatever the situation demands.

It sounds like a whole lot that I described here. Just consider I am a man of many words (well side-thoughts mostly ) It looks more than it really is. Print it out if you need, and read during the pausing of your game during practise. The most important part is to do the sighting and uboot mark plot in one quick sequence. And worry about the rest later. There is plenty of time available in naval warfare.

Really good info. Thank you very much! One note though, on the 2.0 version of the GWX it is harder to use the protractor tool because you can't line it up with the tail of your sub and rely on a not so accurate reading of your course. That make things alot harder because as you know the protractor tool doesn't show minutes, just full degrees.

[Pisces]

True, but I didn't mention that I prepare by first setting 1 leg straight up to north first. Then turn the other leg to my course. You still need to do the angle=360-course in your head though for courses bigger than 180 degrees. Sorry about that. Then you are free to use the 'north leg' again for bearing pointer.

Maybe it's best to learn how to use the attackdisk for this. I don't see how this is taking too long though. The OLC mod automatically adjust for ships course by turning the brown disk. It's only a matter of lining up the bearing pointer to relative degrees, and read off true course on the right scale. (inside yellow scale on the bearing pointer side, or outside yellow scale if you want to read on the far side)

[onelifecrisis]

Originally Posted by Pisces

Maybe it's best to learn how to use the attackdisk for this. I don't see how this is taking too long though. The OLC mod automatically adjust for ships course by turning the brown disk. It's only a matter of lining up the bearing pointer to relative degrees, and read off true course on the right scale. (inside yellow scale on the bearing pointer side, or outside yellow scale if you want to read on the far side)

You can convert any relative bearing to a true bearing at any time using the Attack Disc exactly as Pisces described (and also as shown in the video) and personally it's my preferred method, as it's both quick and accurate.

BTW, good post (further up) Pisces

[Nuoz]

Thanks guys

[Pisces]

Originally Posted by onelifecrisis

BTW, good post (further up) Pisces

Wel, honestly. Credit due where credit is due. You planted the seed in my mind long time ago in some post of yours about keeping the scope up only as long as needed because of detection. Also saying it was reallife practise. I just looked at it in a different light.

[Nuoz]

Hmm that makes me wonder on the method for determining speed. you can count how many second it takes for the target to cross your 0 or 180 marks. Was that usual practice or did they plotted speed?

[onelifecrisis]

Originally Posted by Nuoz

Hmm that makes me wonder on the method for determining speed. you can count how many second it takes for the target to cross your 0 or 180 marks. Was that usual practice or did they plotted speed?

AFAIK as much data as possible was aquired through plotting. When attacking a convoy or lone merchant, you should know the AOB, speed and approximate range before you even raise the scope to fire your eels.

The range/AOB finder and "U-Jagd" chronometer are really for
(a) confirming the above values before firing, especially range or
(b) getting a firing solution on a fast moving task force, or on any vessel which for some reason you can't track over a period of time

But that's just if you want to play "realistic"

[Nuoz]

What kinds of range can one get from the periscope? Would you use it to get an over 1300m range?