Been out sailing around for days and we finally encounter an enemy Vessel! What Now?
Step 1: Don't Panic!
Step 2: Maintain Current orders. We are generally one of the harder things to spot at sea and our watchmen should be better than those merchant marine guys.
Step 3: Consider pausing the game (usually the Backspace key) while we formulate a plan. Real men won't need to but we're lubbers after-all.

Bring up the chronometer (stopwatch) - It's generally the C key. You may need to unpause the game to do this (num pad +) but then repause (Backspace).

Using the pencil place a mark at the bow of the target ship.
Then let time resume... in fact speed it up (a few times) Allow exactly three minutes to pass, then pause it again.

Use the Compass Tool to draw a circle starting at Mark 1 and ending at the bow's new position Mark 2

In this example the distance is 700 yards meaning that the target ship is traveling at 7 Knots.

Notice how there's a second ship following the first? It was common in war-time for ships to travel together whenever possible, even when not in a convoy. It was protection (of a sort) in that if a sub were to target one, the other had a better chance to get away while the sub was dealing with the first.

Generally, if one of the ships was armed it would take up the rear as a sort of mother hen. Since there are two we can be pretty sure that they're on the same course and speed; and we'd be well advised to wait for the 2nd one as it's most likely the fatter target and better armed.

Next use the straight line tool (with the protractor open) to project the ship's course. You can read the course in degrees off that line. In this case 53.5 deg NNE Now extend the line out past where it would pass our sub.

Our immediate goal is to put ourselves on a 90 degree intercept course before they spot us and then submerge to wait for them.

Use the protractor tool to set up a 90 degree intercept course. The first leg should start at their location and come up their course toward us. The second leg should be at a 90 degree angle to the first and be close enough for us to reach it and get submerged before they notice us.



We should plot a direct course to the nearest spot on the line with several other points along that 90 degree line. This will get us there and point us in the right direction. Be aware, as we execute this course, of where they are. Adjust our speed if necessary to get us on the line and "close enough" before they spot us.

Spotting distance may be as much as 9000 yards on a clear day. Luckily in this exercise it's night time which reduces that visibility.

Using the Mark 14 Torpedoes on slow speed we theoretically need to be within 9000 yards as well but even the best skippers couldn't hit much outside 7000 yards. Around 1000 Yards is "close enough." Closer is better up to about 600 yards. Torpedoes need a bit of range to arm. A bit of distance is also good in that our periscope will be harder to spot and they'll not start taking evasive action. (or shooting at us!)

Now that we're on course to our intercept, we should ask the sonarman to start reporting bearing and range of the nearest merchant.

There should be a button for that under the sonar tab

You want to start thinking about "Periscope discipline."
That means:
1) Try not to be going fast when you raise your scope as it will cause a wake they might spot.
2) Only keep your periscope up when it's necessary, at all other times a few feet below the surface is good.
3) Don't always raise the periscope up to full. In calm seas it's best to just get it above the surface. Of course in rough seas you may need to actually rise above periscope depth by a few feet in order to get a clear view.

Look up the target's speed in the chart and find the target bearing.

Our Target bearing will be 346 (360 - 14 degrees since they are approaching from port)

The method I'm using is called the O'Kane method. It's simplified in that all of the calculations are worked out in a leisurely manner.

• There's really no need to exactly identify the class of merchant you're shooting at.
  
• Angle on Bow need not be determined under time pressure.
  
• Range doesn't matter (that much)

Provided that the target is within range of your torpedoes, the exact range doesn't matter all that much. The solution you determine for 1000 yards will work at 600 or even 6000, though at longer distances everything that goes into it must be more precise.

This table is derived from a triangle where the vertical is the distance a torpedo travels at 31 knots while the base is the distance a target travels at any given speed. The angle at the top of that triangle is our "Target Bearing". If the vessel is approaching from starboard it's the number itself.

If (as in our example) the target is approaching from port, then 360 minus the number gives us our target bearing.

Angle on Bow is simply the difference between 90 degrees and that bearing.

Of course knowing when to add or subtract is required of the skipper based on whether the target is approaching from port or starboard. The same holds when firing rear torpedoes, but then the target bearing is 180 plus or minus the target bearing

During World War 2 ♥♥♥♥ O'Kane served in the highly successful USS Wahoo as executive officer and approach officer under noted Lieutenant Commander Dudley "Mush" Morton until being promoted into a command in his own right. O'Kane participated in more successful attacks on Japanese shipping than any other submarine officer during the war.

Submariners still call the method I'm describing here the ♥♥♥♥ O'Kane 7000 yard method.

Position the scope at the target bearing and open up your TDC

That's the 90 degrees that we expect to impact at, minus the 14 degrees that we're leading the target.
Set this AOB by...

• 1 Spinning the wheel
  
• 2 Stop at Starboard 76
  
• 3 Press the enter button

• 1 Spin the wheel
  
• 2 Stop at Speed 7
  
• 3 Press the enter button

• 1 Move the plastic bracket clockwise stopping at max
  
• 2 Press the enter button
  
• 3 Do NOT use the split-o-meter to set any range for this method

The top portion will show your target and the AOB, Range and Speed you've entered



The bottom portion will show your ship's (intended) position



If not on the position keeper display, toggle that at the bottom left.



Do NOT activate the position keeper by clicking on the round red button



1 Torpedoes should default to slow setting -
if using my 31 Knots chart do NOT change this

2 Torpedoes default to influence triggers.
While either will work, influence exploders have the ability to cause more damage when they function properly.

3 Check that you have a zero degree offset.
This generally isn't necessary when using this method and if NOT zero will mess up your results.

4 Adjust the depth. The default is almost always too shallow.
If you're hunting merchants or capital ships 20 to 25 is a good guess for a large merchant. Deep running torpedoes are inherently more reliable than those set to run too shallow. They're also a bit harder to spot due to the wake. The ideal depth for an influence triggered torpedo is a foot or two BELOW the ship's keel depth. An explosion just below the keel can "Break the Back" of a ship which guarantees a kill.

You'll need to to open the torpedo doors for each torpedo that you intend to fire. Each skipper has to develop a routine as to when to do that. As you check each torpedo might be a good time.

)

If you've entered the correct Target Bearing, Speed and Angle on Bow you should see your torpedo track coming out directly toward zero (for front facing shots or 180 for rear facing shots)


A variance of a degree or two is not an issue for short to medium range shots. For longer shots a slight adjustment to your course (via rudder?) might be required.

Larger variances suggest that you have something entered incorrectly or you forgot to enter one of the variables.

If all has gone to plan you'll find that you're all set-up to fire and just waiting for those laggardly merchants to arrive.

Now might be a good time to try and ID the ships you're waiting on.

Of course this requires you move the periscope off the pre-determined target bearing. There's no harm in that but do NOT change any of the TDC info and remember to reset the scope on the correct bearing when you're through.

With a smokestack in the back, this is probably a tanker. With all those masts , I'm guessing that this is a "Medium Cooler." Not that the draft on this is 25.6 so our guess there seems right. However this is the lead ship and I'm not seeing any gun on his forward gun platform so we may be able to get a two-fer. Sink the trailing ship with torpedoes, then surface and take this guy with our deck gun. The sea certainly looks smooth enough. Course smooth seas are even more reason to get the scope down for a bit.


This one's further away and harder to ID. Mid stack so likely a freighter of some type. Pretty modern bridge. Two masts with a wire between. According to the ID book likely to have fore and aft guns. So this one gets the fish. Also the draft is pretty close to our guess so we're OK there.

If you can't ID the ships from the recognition manual you CAN ask one of your crew to do the honors via the ID Target button that's displayed when you're at the attack periscope. When they sucessfully ID a ship, the ship type will be shown in the left TDC control box if you've got it set to Position Keeper.

They say that warfare is 95% boredom and 5% sheer panic. Guess which part we're in.
If this were a game I suppose we could save a copy here so that if we screw this up, we could come back and try again. ( Ya know for the learning experience... or in case we want to take some pictures or something...)

The sonarman is still calling off the bearings (But for the lead ship) and we decided to take the second one. We could watch them on the navigation map and accelerate time I suppose as long as we don't cut it too close.

Finally the lead ship has passed us and the trailing ship is getting close to our target bearing.

I always get the yips about now. It took me three tries to get these pictures and they still aren't perfect but...

With this method and at this range it's all about picking your spot. I waited until the bow had passed and fired my first torpedo. Ships with holes in their fronts tend to take on water.






I know it's a bit early. The best place for that second shot is just below the mid smokestack. It tends to be where the ship's power plant is and I hear they don't run well full of water.






Told ya I get the yips! I was so busy placing the shots that I didn't get a pic of the third torpedo target placement. One hit back near the propellers may stop em dead in the water. Always a good spot.

Yeah, four torpedoes is probably overkill for this type of ship but at $10,000 per fish, I'm guessing it's a bargain. Their ship probably cost them more than that. And there's the cargo. Plus with the armed one outta the way I can use my guns on the leading tanker.

Also, I wanted to show off the hit rate you can expect with this method. (There's also the HIGH possibility of a dud)

If you opt to run with 100% realism you can't use the external camera but I kinda like the cinematics.
Musta woke someone up. They've got their searchlight on trying to mess up my photography.
Got the report from the crew that she sank while I was out taking pictures.

Set a course for that cooler, surface the boat. All ahead full. Man the deck gun and lets sink that tanker.

A convoy is a flock of Merchants protected by destroyers with front-facing radar.
The secret is to get ahead of them while at a distance after determining their course & speed
Get perpendicular to their course.
Go deep (below the thermal layer ) and wait...
When the leading destroyers pass you by, the sonar picture changes
Then rise to periscope depth.
I don't know what I'll find, but I've a preset solution given their speed of 11.5 knots. Shoot as the targets pass my target bearing. It's possible to get two hits each on two ahead and two astern as the more distant torpedoes take longer to get there and the warning time is decreased.

Of course once you fire, go deep and quiet and slink away a bit. You can always come back up when the hornets calm down and finish off any stragglers.

Here is GuybrushK's masterful video on targeting a small convoy. Of course this basic methodology will work with unescorted ships as well. It's not QUITE as precise as the method I describe but is a LOT more flexible.