How to do a sonar approach in fog?

[tmdgm]

Saw this mentioned in another post. I understand how to do manual targeting, but how do you do a sonar approach in fog? Sonar shows bearing and range, but range is short, med an long. How do you get range from sonar?

[The Butcher]

There is a Sonar targeting training mod available. It loads as a single mission. The challenge in the fog is you need to know what kind of ship it is in order to estimate speed by the prop rpm. You can also try the 3:15 rule to get close. The documentation for the training mod includes a chart that gives you the firing bearing for every ships speed. It is tough to get a hit but it is so cool when you do. I would suggest firing a salvo, it increases the odds. There may be another way but tha is the one I know.
http://www.subsim.com/radioroom/showthread.php?t=107303

[tmdgm]

Thanks, I'll give it a shot

[Brag]

Butcher, welcome aboard!

Good advice.

Another method (depends if merchie is armed or not). Get in front of the ship and ducpilcate it's course. Let him sail ahead, surface, get him in sight, blast her with one magnetic torpedo from 250 meters

[The Butcher]

I've done it that way with AI targeting but it happens too fast for me to do manually. It will really take some time now that I'm using the OLC GUI. It is sweet but it's like starting over. The Sonar trainer is slick too. This is my first sim game and as my wife would tell you, completely obsessed. It's crazy!!!

[Slang]

I have a way that i do it, but without active sonar it takes a whole lot of time to set everything up.

First you should be able to tell roughly what the ship's heading is. get close to it then go to periscope depth. Let the ship pass by you then get into a position directly behind it. next turn your boat so you are pointed directly at it and the sonar man calls out a bearing of 0 degrees. he should be set to give you constant updates.

So now you're pointed at him directly behind him at ahead standard. You should notice that over time he will start drifting a few degrees right or left. This is because unless you got really lucky the course of the two ships are not exactly the same. But this is what we are trying to do, determine his exact course. You need to correct the course of your boat until the target reads a steady 0 degrees over several minutes. You now have his exact course. make a note of his true heading. On the nav map, draw a line from your boat out along this heading. As this line is passing right through him we will use it for range and speed calculations later. Also you need to be as accurate as possible with it.

Next, break contact, surface the boat and run up ahead of the target at flank speed. Position your boat to be around 500-800 meters from the predicted track, at a 90 degree angle from the track. This is important, make sure you are perpendicular to his course. Also be sure you run up far enough cause if you don't everything will be rushed.

Anyway go to peri depth and ask for a report on the nearest sound contact. make a note of the bearing and start the chrono. (Actually the sound man gives u a basic speed of slow, medium, or fast. As this is such a short range shot u don't really need a super precise speed measurment. just type in 6 or 7 for slow and 9 or 10 for medium. I woulnd'nt bother with fast targets.) But we can find an accurate speed anyway if we want to. Draw the bearing your sonar man indicated until it intersects with the predicted track we already drew. Now you need to wait some more. If you have a Nomograph mod you can determine how many minutes you want to wait. If you don't have a nomograph u need to wait 3 minutes 15 seconds. after the time is up ask for another sonar update. Mark the targets position as before. next measure the distance between the 2 points we just made. Use the Nomograph to calculate speed. Or if you did the 3:15 thing then the distance between the two points will be his speed in knots. ie... 0.7km is 7 knots, 0.9km is 9 knots etc.

Now setup your torpedos. go to the periscope. You don't have to raise it above the water, just so you can see the marks. Make sure its pointed right at 0 degrees. Now go to the TDC and enter the speed you just calculated. Enter 90 degrees AOB either port or starboard depending on the situation. Set up depth, torpedo run speed and spread as you see fit. next switch the TDC back to auto so it will update the solution. Go back to the periscope and swivel it until the gyro angle reads 0 degrees. Make note of the pericopes bearing. It should read between 10 to 15 degrees for a fast torp and slow target. This is the bearing the target needs to be at when we fire. Go to the nav map and draw a line out from your boat along the periscope's bearing until it intersects the predicted track. This will be his precise range. Go to TDC and enter this range value. The boat must not move at all now. Make sure tube doors are open.Now all you have to do is wait for your sonar man to tell you he has reached the correct bearing. Fire and wait for the sound of explosions. Congrats you have just hit a target without ever seeing it. Better hope it wasn't a neutral.

Anyway, good luck. I hope this helped, and actually made sense to somebody.