Angle on Bow "AOB" is a term many new players can struggle with, yet it is essential to know if you want to fire accurate torpedoes.

This guide is dedicated to educate curious players and aspiring captains to know what the AOB is, how to figure it out and what you can do with it once you know it. We will also describe the relationship the AOB have with bearing (magnetic/relative), your course and the convoys course.

You may have come across the term "Angle on Bow" or its acronym "AOB" and have yet not understood it. Here it will be explained.

If we look at the term word for word and start with "Bow".
The "Bow" of the ship is it's "Fore"/"Front". The ships rear and side also have other names such as "Stern" which can be used instead of "Aft" or "Rear" and the ships side can be referred to as it's "Beam".

So the term "Angle on Bow" means the angular difference one need to turn in degrees away from the "Front"/"Fore"/"Bow" of the ship.


In other words, you can imagine that you can see the ship's lookout and they see a enemy sub (your sub) so they therefor will be calling out in which direction they see the enemy sub. Imagine that the same time they also will be using their entire arm and point towards the sub it. The direction of the arm and what the lookout will say is the Angle on Bow.

Do note that it does not matter your distance, how fast or what course you have when it comes the AOB.

When you are observing a ship to determine it's Angle on Bow to you you can use various methods but some of the best indicators to tell the AOB is by using ships Masts, Funnels and Kingposts.

The "Funnel" is the chimney/smokestack and is usually located in the aft or amidship however the funnel is always in middle of the ship to prevent it from listing to any side due to offset weight distribution. A "Mast" is anything that is not a funnel, kingpost or superstructure. There is many different mast shapes and they can be positions anywhere on the ship but what the all have in common is that they are always centered (like the funnel) over the keel. This allows you to see the funnel and mast align perfectly when a ship is moving directly away(AOB 180°) or towards(AOB 0°) you .

Some ships have masts with "Derricks". A Derrick is lifting equipment like a crane used for cargo that is attached to a mast. These derricks can be used to estimate a ships AOB. When the derricks align behind each other or behind the mast they will form the shape of an downward pointing arrow 🡣. When this happens the ships AOB can be either 0°, 45°, 90°, 135° or 180°, so its good to combine derrick alignment with other observations such as kingposts and superstructures to not make a bad call.
However some masts with derricks are more suitable to use than others. Some are rotated and some are just too small to see that they will give a incorrect picture of what angle on bow the ship have. You can determine if a mast with derricks will work by identifying the ship and if the mast in the recognition manual only displays 2 arms, then in most cases it is usable.

The Kingpost is the "H" shaped construction on some ships. Unlike the mast the kingpost comes with two posts paralleled to each other with a beam connecting them in between. They will many times have one boom/crane attached to each posts which can be faced towards the front or the rear. When the kingpost is aligning its both posts behind each other so you no longer can see the connecting beam then the ships angle on bow is 90°. However due to the thickness of the posts it can be hard to see when both posts is perfectly behind each other as it can appears to be aligned yet be multiple degrees off 90°. It's good to use other methods in combination to verify that the AOB is 90°, for example one can use a mast with derricks.

While superstructures and island are really hard to get a definite angle on bow from you can use it in combination of other methods to rule out potential errors. You can for example use it together with mast with derricks to determine if you are closer to a 90° rather than a 45° or 135°. The way you can tell is by looking on the shading of the superstructure(s) and see if you see two different degrees of light levels on the wall then the ship is probably not aligned to the 90° but rather towards 45° or 135°

Click image to enlarge
You can see the bridge and you can see the kingpost overlapping the funnel (As funnel can only be aft or amidship) you can determine that you are not viewing the ship from its aft but front. The mast and funnel is also aligned and the spacing between the kingposts and mast is even.


Click image to enlarge
You can still see the bridge windows which suggest it is still coming towards you. You can also see that some superstructures have a different shading on the wall which would suggest you are sing two sides of a geometric shape. The derrick coming of the mast is aligning behind each other forming the shape 🡣 yet the Kingposts is not align and still showing a shape of a H, it therefore suggest it is not at 90° AOB but something less and close to 45°.


Click image to enlarge
When the kingpost is aligning in such a way it looks like one thick mast and the mast with derrick is forming the shape 🡣 you could be certain the AOB is 90°. This can be strengthen by not seeing only one of the faces of the superstructures.


Click image to enlarge
The bridge windows will be obscure which suggest its going away from you. You can also see that some superstructures have a different shading on the wall which would suggest you are sing two sides of a geometric shape. The derrick coming of the mast is aligning behind each other forming the shape 🡣 yet the Kingposts is not align and still showing a shape of a H, it therefore suggest it is not at 90° AOB but something less and close to 135°.


Click image to enlarge
If it is going away form you will be unlikely able to see the windows of the bridge and if the funnel is located in the aft then you can see it overlapping the super structures. The mast and funnel is also aligned and the spacing between the kingposts and mast is even.

You can also get a ships AOB mathematically. This can be done by this formula:

l = Measured Centiradians Of Ship Length (°)
h = Measured Centiradians of Known Height On Ship (1/16°)
L = Length Of Ship (In meters)
H = Known Height On Ship (In meters)

AOB going towards you:
AOB going away from you:
Converting Radians to Degree:

Example:
Identify your ship (click on link for guide) and then measure the ships dimensions with your periscope. Determine if the ship is going towards you or away from you (in this case you can not see the bridge windows, so it is going away from you.). You must also observe if its going towards "left" or "right" (in this case "Left")

Then fetch the ship dimension data form the in game Ship Recognition Manual.

As we know its going away from you, we will use that formula and we replace our variables with our numbers:
We can then assess that the ships AOB at the moment of observation was "125.2° Left"

NOTE: This is not the most accurate method, while your math may be solid, your ability to estimate the dimensions of the ship with your periscope and get it in degrees & 16th of a degree can be unreliable (due to waves and the uboat not maintaining stable as well as you using your eyes to measure the distance between the lines on the periscope.) and your result can vary with several degrees of what the AOB is in reality.

Once you have determine the Angle on Bow of a merchant ship in the convoy there is multiple usage of that.

If you are directly behind(AOB 180°) and using your attack periscope, you will know the ships course from observing the bottom magnetic bearing.

In this example the ships course is 030°. Because its AOB is 180° and magnetic bearing is 030°
If you were directly in front (AOB 0°) you can just add or subtract 180° to the magnetic bearing and you will have their course.

With this method you can also, for every ship you cross their AOB 0° or 180° draw their course on the map. This way you can temporary get an idea of the width of the convoys formation which might help you plan your attack

If you see a ship with AOB 90° and turn your U-boat so the target is at your 090° or 270° relative bearing, then you are traveling in the same direction and you will be on their course.

When you know a ships AOB take note of it's magnetic bearing with the attack periscope (or using any other method)

Example AOB 90° at Magnetic Bearing 329°

We should remember this bearing so optionally we can make a graphical note of it using the map tools:

1. Open the map, enable "Show Angle" (OPTIONAL: Disable "Show Distance")
   
2. Use the "Draw Line" Tool and start drawing a line but type in the Magnetic Bearing using your numpad on your keyboard. In the case of the example above, you type in 329.
   
3. Do note that the line now locks into 2 directions: 329 & 149 depending the position of your mouse cursor. Move the mouse cursor so that the line is drawn for 329.

For the next step you will use this information to convert the magnetic bearing into the course of the target. There is a formula to follow when doing this:

[Mag ber] = Magnetic Bearing of a target and its know AOB
[AOB] = Known AOB of the target

If the AOB is left, then you will use - if the AOB is Right you will use +

Here you might be able to see the relationship a bit better:
180° - [AOB] = ?

• If AOB: 0°, then: +/- 180°
  
• If AOB: 45°, then: +/- 135°
  
• If AOB: 90°, then: +/- 90°
  
• If AOB: 135°, then: +/- 45°
  
• If AOB: 180°, then: +/- 0°

In this example, where we saw the target, the target is at Magnetic bearing 329°, at a AOB of 90°, on the left side. The formula will looks something like this:


But we can use the map table's built in calculator for this!

1. Start drawing a line from the end of the magnetic bearing line you drew before
   
2. Type in the Magnetic bearing for the target you observed using your numpad
   
3. press the
   
   • numpad + if the target is at a AOB Right
     
   • numpad - if the target is at a AOB Left
4. Using the numpad type in the amount of degrees you need to +/- with in order to convert the bearing to the course as described above.
   
5. Finnish drawing the line by left clicking with your mouse in the direction:
   
   • Left if you used num -
     
   • Right if you used num +

Keeping the "Show Angle" enabled allows you to see the course to be: 239°

Once you get comfortable using this method, you can determine the course really quick when you notice a know AOB and know its magnetic bearing.

So if you set the TDC up with the correct AOB yet you do not know the course of the convoy nor are you matching your subs course with theirs course. Then you can set angle tracking to AP and have a crewmember watch the AOB dial on the TDC while another one is turning the Attack Periscope until the AOB shows 180°. If you then check the magnetic bearing you can then read the convoys course. This can be done in similar ways as well while crude it is simple enough for everyone to understand.

If you know the convoys course and need to put it into the TDC, then turn angle tracking to AP and ether do:

• Order your sub to assume the convoys course and then turn your Attack Periscope to your 000° relative bearing. When looking towards your 000° relative have the TDC's AOB set to 180°
  
• Turn your Attack Periscope to the convoys course using the magnetic bearing indicator. When looking in the direction of the convoys travel, have the TDC's AOB set to 180°

Note that this can be done with other directions and other AOB's. Once you understand the concept you will be able to be more flexible when setting AOB on the TDC.

Because all merchants (unless provoked) will travel with the same course, you do not need to change the AOB for each ship independently. Once you have set the AOB for one of the merchant you have set it for all. Do note that if the convoy have been spooked, all merchants will zig-zag to evade torpedoes and after they calmed down they will form up again in formation but their course might have changed and so their AOB. When playing at hard difficulty the entire convoy will zig-zag from time to time (but with high probability around 20 mins after last zig) thus changing their course.

If you have your TDC set up with angle tracking on to AP, OP or UZO you then do not need to worry about you moving ahead, behind, further or closer nor does it matter if you are turning your sub or change your own speed, the AOB setting will still be correct as long as the convoy maintains their course.

Do not use the Escort/Warships ships to estimate AOB on. They zig-zag (regardless difficulty) to constantly prevent them from getting hit by torpedoes so you can not use their AOB to shoot on the merchants.

AOB can take some time to get your head wrapped around, this is not unusual. So do not get discourage just because it seams intimidating in the start. You can play the tutorial missions in the game that allows you to reveal other ships positions and targeting data which might help you out. You can also access the games official manual from the main menu where it will also explain many things for you.

Discord
If you might need more help, you can always try to join the Official Wolfpack Discord[discord.gg] and ask around there for help or see if you can join a experienced captains game and check if they can teach you in person. There is many nice experienced player that are eager to share and teach players the game.

Translate
If you want to make a translated version and publish it on steam, let me know and I will link to it in this guide as long as you clearly make a mention that it is a translated copy of this version and provide links to this one in yours. Also if you want to make your own additions to it add it under Authors Words in a section called something like "Translators Words"

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