The Type II U-boat was designed by Nazi Germany as a coastal U-boat, modeled after the CV-707 submarine.
Most Type IIs only saw operational service during the early years of the war, thereafter remaining in training bases. Six were stripped down to their hulls, transported by river and truck to Linz (on the Danube), and reassembled for use in the Black Sea against the Soviet Union.
The defining characteristic of the Type II is the small size, its surfaced displacement being between half and one third that of the Type VII, and one third to one fourth of the Type IX's (depending on the variants used for comparison). Known as the Einbaum ("dugout canoe"), it has some advantages over larger boats, chiefly its ability to work in shallow water, dive quickly, and increased stealth due to the low conning tower. However, it has a shallower maximum depth, short range, cramped living conditions, and carries fewer torpedoes.

The interior is very basic with no bulkheads separating each compartment. Layout front to back:
1. Torpedo room (Yellow)
2. Control room (Blue)
3. Engine room (Red)
4. Berthing area (Green)

Ballast tank 1 (green)
Bow trim tank (black)
Torpedo compensating tank (red)
Regulating tank (light blue)
Ballast tank 2 (yellow)
Gravity fuel tank (orange)
Main fuel tank (orange)
Stern trim tank (Pink)
Ballast tank 3 (Dark blue)

1. Open air intake (roof of engine room)
2. Open both exhaust output valves (If exhaust blowing open exhaust blow valve and keep output valves closed)
3. Open gravity fuel tank fuel valves (optional)


1. Set engine mode to run (3rd position)
2 Increase throttle
3. Open the starting air valve
4. Once the engine starts close the starting air valve
5.Set engine mode to run (1st position)
6. Repeat for the other engine
7. Once both engines are started enable the clutches

Keep in mind to increase the throttle enough so that the engines don't stall when engaging the clutch.


One of the key parts of managing these engines is responding to orders from the captain or the helmsman. To do this efficiently you have a panel which shows the RPM's for each speed.


Slow speed 250 RPM
Half speed 350 RPM
Full speed 550 RPM

Once you get the speed order refer to the table and adjust throttle so that the RPM approximately matches the RPM for the desired speed.


1. Disable clutches
2. Set engine mode to reverse (2nd position)
3. Enable the clutches

If you just set the mode to reverse without disabling the clutches the engines will stall.

1. Make sure main power is on
2. Turn on the motor power
3. Increase throttle


Managing the motors is the same as the engines. The main difference is the RPM table, which has different values, given that the motors aren't as powerful as the diesel engines.


Keep in mind to adjust the throttle as the battery loses charge. Failure to do so will result in the motors slowing down and a noticeable speed decrease.


Enable motor direction switch

The compressed air system is essential for blowing the ballast tanks, starting the engines, filling and emptying torpedo tubes and also firing them. The system is made up of 4 main air tanks, an electric compressor and the piping necessary for the system. You also have dials in the control room and in the engine room to monitor pressures.


When the compressed air pressure is low enable the electric compressor.

1. Make sure main power is on
2. Enable the electric compressor
3. Open both of the compressor air valves

To turn it off make sure to close the compressor air valves before turning off the compressor.


Compressed air usage is controlled from the control room. The only thing that you need to touch is the main blow valve to blow the ballast. The other valves should only be used in emergency situations.

The electric system on the type IIa is very basic. You have on main battery compartment and a control box in the engine room.

The control box allows you to enable the main power and the nav lights. Battery charge is shown in volts and usage shown in amps.

Before diving you can check the depth below keel using the depth finder in the listening room

1. Sound the dive alarm to notify the crew (if playing in mp)
2.Close the air intake, exhaust output valves, stop engines and engage e motors (done by engineer)
3. Open all ballast tank vents
4. Either control the dive planes manually or set the automatic depth hold (positive numbers)


Ballast tank 1 has one valve on the roof of the control room near the front
Ballast tank 2 has two valves on the roof of the control room near the middle
Ballast tank 3 has two valves on the roof of the control room near the middle

1. Close all ballast tank vents
2. Open the main blow valve
3. Set auto depth to 0 to turn it off and adjust the dive planes so the boat pitches up


Note that you don't need to use all of the air in the compressed air system to blow the tanks fully. Just blow the tanks for a few seconds and then you can finish blowing the tanks using the exhaust from the engines.


You can also use the exhaust from the engines to fully empty the ballast tanks.
Once the conning tower comes out of the water instead of opening the exhaust output valves, open the exhaust blow valve (in the engine room), after that open the exhaust blow valves in the control room to start blowing the tanks using the exhaust from the engines.


The ballast tanks do not have any indication of fill level. The only way to know when the tanks are empty is by surfacing and checking how deep the boat sits in the water.

The type IIa has a single pump in the control room. The pump has many uses, it can be used as a bilge pump, you can use it to move water between the trim tanks and the regulating tank.


The pump is quite simple top use. The pump has one input and one output. There are valves that connect to each.


1. Open the torpedo room and control room bilge pump connections
2. Open the water outlet connection
3. Enable the pump

Don't forget to open the torpedo room drain in the front of the control room


1. Open the water inlet
2. Open the pump inlet
3. Open the regulating tank port and the pump to regulating tank
4. Enable the pump


1. Open the regulating tank port and the pump to regulating tank
2. Open the water outlet connection
3. On the compressed air control panel open the regulating tank valve and close the ballast tank valves
4. Open the main blow valve to blow out the water from the regulating tank


The pump allows you to pump to and from whichever tank or place you want.

If you open the pump output connection for a trim tank then it will open a valve between the pump output and the tank input. This will allow you to pump water in to the tank.

If you open the pump input connection for a trim tank then it will open a valve between the pump input and the tank output. This will allow you to pump water out of the tank.

When pumping water into the tanks you need to open the main pump inlet and water inlet.
When pumping water out of the tanks you need to open the the main pump inlet and the water outlet connection.

The submarine is designed to reach neutral buoyancy when it has 3 torpedoes loaded in the torpedo tubes, an almost full fuel tank, no water in the regulating or trim tanks.

As you use fuel, fire torpedoes the submarine will lose wight and will no longer be neutrally buoyant. To account for this you have a regulating tank and 2 trim tanks which you need to use to get close to neutral buoyancy.


The dive planes give you precise depth control when the submarine is in motion. These can be controlled manually (control is quite easy when the sub is close to neutral buoyancy) or automatically using the depth hold.


The depth hold is enabled when a depth has been set (positive numbers) it is disabled when the depth is set to 0.

The hydrophone is not made by me just slightly modified to fit the submarine better.

https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3001543907&searchtext=hydrophone


Using the arrow buttons turn the hydrophone and listen for a contact. Once you hear a contact you will know the relative bearing to it, there is no range information.

The hydrophone also has simulated sounds which are really cool!

The radio on the type IIa is super basic. It only works with morse code (sending and on/off signal on channel 1 on the selected frequency/channel)


1. Turn on the power switch
2. Set the channel
3. Using morse code send signals


1. Turn on the power switch
2. Set the channel
3. Listen for morse code beeps

Historically the type IIa mainly used TI and TII torpedoes, but you can use whichever torpedo types you want.





The TI and TIII torpedo types have modified variants which incorporate the FAT (Federapparat) system. The system allows the torpedoes to go in a search pattern if they miss their intended target.

To activate the system set the system activation range (on the stern of the torpedo). The range should be beyond the target range (so the torpedo passes the target before going into the search pattern). The system allows you to set the direction of the search pattern. If the FAT direction switch is off the torpedo will start the search pattern going from left to right, if the button is on the search pattern will be from right to left.


There are two main things to keep in mind when maintaining the torpedoes. Damage and charge.

Damage is self explanatory, a damaged torpedo is unlikely to work properly so make sure they don't get damaged and if they do make sure to repair them.



The electric torpedoes need to be recharged from time to time, this is an intended feature. You don't really have to worry about it, but if you are doing a long sub-hunt or just playing around for multiple hours recharging the torpedoes becomes quite important.

Keep in mind that the homing torpedoes need to be recharged more frequently, than the straight running ones.



The torpedo charge panel shows the torpedo charge in volts 120V=100%. Amps show charge speed. Keep in mind that to charge the torpedo to full the main battery of the submarine has to be fully charged as well, if it isn't the torpedo will lose charge instead.

1. In the editor select the selection grid
2. Load content
3. Open the torpedo set
4. Move it under the submarine and paste it in
5. Select the torpedo you want to use
6. Copy or cut it
7. Move it in the submarine (torpedo tubes or reserve)
8. Paste it in
9. Before spawning in the sub delete the torpedo set



1. Fold beds
2. Release the track brakes on the bottom of the torpedo
3. Pull out the torpedo using the handle
4. When the torpedo mostly clears the top bunk activate the bottom track brake
5. Move the torpedo loading rail over the torpedo
6. Lower the rail so that it attaches to the torpedo
7. Activate the brakes on the top rail
8. Release bottom track
9. Lift up the torpedo
10. Open the torpedo tube hatch (make sure to drain the tube beforehand)
11. Align the torpedo with the tube (can be quite finicky)
12. Release the top rail brake and push the torpedo in (can be quite finicky)
13. Make sure the torpedo clicks into place



1. Torpedo tube vents
2. Open the drain/fill valve
3. Release some compressed air into the compensating tank by pressing the fill torpedo tubes button
4. Check the fill level, once it is almost full you can turn everything off and open the external doors

Note that you don't need that much compressed air to fill the tubes, only open the torpedo tube fill valve for a few seconds


1. Close external doors, make sure torpedo tube vents are closed
2. Open the drain/fill valves
3. Turn on the empty tube buttons
4. Open the torpedo tube blow valve
5. Once the torpedo tubes are mostly drained you can open the doors

Again don't use too much air to drain the tubes


You do have the possibility to manually reload the torpedoes, but I really haven't had the chance to test or perfect this. You can try using a crane with mag all's.

There are two periscopes on the type IIa. The attack periscope in the conning tower, and the observation scope is in the control room. Both periscopes can be used for attacks and general use, but the attack scope is slightly better because it goes up further than the observation scope.



The TDC (torpedo data computer) calculates the gyro angle and the spread angle from the information given to it. The outputs are then sent to the gyro angle receiver.


Torpedo speed is very important when using the TDC. There are 2 different speed options, 30 knots and 39 knots. 30 knot setting is used when firing electric torpedoes and the 39 knot setting is used when firing steam torpedoes.



The easiest way to figure out the AOB is to imagine that you are on the enemy ship looking forward then you turn left or right to look at your sub the amount of degrees that you turn is the AOB. When inputting this value into the TDC positive AOB means target is moving from left to right and negative means from right to left. This value is super important for the calculations to work properly, sadly the only way to figure it out is to look at the target and estimate/guess depending what you can see.


Speed can be calculated by putting the periscope in front of the enemy ship then when the front of the ship passes the center vertical line start the timer. When the stern of the enemy ship passes over the same vertical line stop the timer. Then take the ships length and divide it by the time that the ship took after that take that value and multiply it by 1.8. The problem with using this method is that you need to know the length of the enemy ship and when measuring the time you need to be either fully stopped for the most accurate result or moving very slowly. This can be very hard when underwater because for precise depth holding you need speed for dive planes.

Another way to calculate speed is to go along side the enemy ship and try matching speeds, this is also quite hard and it does take time but it can be more accurate than the first method, if you are moving.

Experienced captains during the second world war were able to guess the speed by looking at the smoke of the ship and other factors.


This value isn't super important, but you should still put in something for the calculations to work. Range is used for calculating parallax and spread.

I recommend trying to estimate the range to target from what you can see.


You can set the relative bearing manually or just take the bearing from the periscopes.

Manual bearing is quite simple, look at the front of your submarine, then turn to look at the target and the degrees turned is the bearing.

Scope bearing is what is normally used. Select the periscope you want to use on the fire control boxes, turn on optic follow up in the conning tower and using the selected periscope look at the target, make sure to put the vertical line in the center of the scope screen, where you want the torpedo to hit.



The fire control boxes control how the attack is conducted. They allow you to select which periscope you are going to be using for the attack, they are used to select which torpedoes you want to fire and which firing lever you want to use.


0 - None
1 - Attack scope
2 - UZO (not implemented on type IIa)
3 - Observation scope


0 - None
1 - Tube 1
2 - Tube 2
3 - Tube 3
4 - Spread


Only used when firing a spread shot, position 4 needs to be selected on the torpedo selector.

0 - None
1 - Tubes 1, 2, 3
2 - Tubes 1, 3
3 - Tubes 2, 3
4 - Tubes 1, 2


0 - None
1 - Top of conning tower, UZO column (not implemented on type IIa)
2 - Inside of conning tower



The gyro angle receiver receives gyro and spread angles from the TDC and passes them on to the torpedoes. It also allows you to manually set the gyro angle (used in emergency's or when firing homing torpedoes). It is important to turn on the spread shot button when firing a spread shot, if this is not set the torpedoes will not receive the spread angles.


The torpedo tubes are self explanatory, but I do want to mention that they do allow you to set torpedo depth.

1. Prepare tubes for launch (load torpedoes, flood the tubes and open the external doors)
2. Set torpedo depth
3. Set fire control boxes (depending on the situation)
4. Set torpedo speed (steam torpedoes 39 knots electric 30 knots)
5. If firing spread shot select spread shot on the gyro angle receiver
6. Turn on optic follow up
7. Measure and set enemy ship speed
8. Set AOB
9. Set approximate range
10. Set the width of the spread shot in meters, usually slightly less than the length of the enemy ship (if firing spread shot)
11. Look at where you want to hit the enemy ship with the periscope and launch

Don't forget to turn off the firing lever after all of the torpedoes have fired (or a single torpedo)

The maximum gyro angle for the torpedoes is +90 and -90 degrees, if the firing solution requires a larger gyro angle, the torpedoes will not be able to follow. If the TDC shows a gyro angle higher or lower than +90 or -90 degrees you need to maneuver the boat so that the gyro angle is within limits.

When firing homing torpedoes set the gyro angle to 0, point towards the target, launch the torpedo and dive deeper, so the torpedo can't turn around and hit you.

The system is very accurate and reliable if you miss it usually means that the information given was incorrect.

Hope you like what I did here, if you have any questions make sure to let me know, if you find any issues with the creation or the manual let me know as well.