I play with 84%, WE on only for identifying some ships im not sure of not for ploting solutions (i do it myself) and external camera for eye candy only. I find my contacts position trough the hidrophones and visual observation (periscope/uzo) you dont really need to know where your sub is to do this, the stadimeter is only for calculating the targets range mate, but the all purpose of my first question is that normally i make the 90º AoB approach, but sometimes its not possible to make such an approach and i wanted a fast way to calculate the targets course to determine the AoB in other angles than 90º.

I used the draggable version before and it was very usefull, but since i removed the sub icon from the map i cant make the nomograph to show on the map no more:nope:.

A substitute for the 3 minute, 15 second rule
 

Distance in Kmeters x 32.5 divided by minutes = knots
Or distance in meters x .0325 divided by minutes = knots

Plot target's first position and begin timer. Plot subsequent positions and plot target's general course. Measure distance traveled and note minutes on timer.

For example 2.6 Km x 32.5 divided by 12 minutes = 7.0416 knots

The more observations and calculations you make, the more accurate your estimation of speed.

This is really useful with a target on a zig-zag course.

3:15 rule is not to get course, but rather speed. As the distance between plots made with 3 min 15 sec's seperation is equal to speed in knots/10. So make the plots seperated with 3:15 and measure the distance between plots in meters. Now multiply that with 10 and voila - Knots.



Now if you ARE looking for target Course

Then that realy depends on what info you have available on the target at hand.



1---
You could use the whizwheel if you have
A) own sub's heading B) Bearing to target C) AoB

2---
a Second method is simply plotting it from WO's calls - never mind the time seperation as you dont need speed to have course from the plot.

3---
the third and most dificult way (also not very WWII'ish) is TMA on hydrophone plots. TMA = Target Motion Analysis. This is VERY dificult and time consuming, but if your a NERD i guess it could be a fun and tormenting study. Hit words for Google would be Ekelund Range, TMA, Geo-plot, one-bearing only. I'm simply do not know enough about this to be able to tell you about it my self.


As for the plotting it self - mummit is 100% right. You dont need jack but a paper and a set of rulers to plot. Make a north arrow on the paper - now make a line that has your sub's course. Now make small hacks on that line with the interval in scale that your sub at current speed will travel in 3 min 15 sec's. Make lots of hacks.

Take a bearing Range reading of the target - start the stopwatch and then plot that at the first hack. As the stopwatch comes to 3.15 make the next plot from the second hack. At 6.30 the thired plot from the thired hack etc etc etc. Soon the target plots will show a direction - connect the dots and voila - course. Now measure the speed from the plot spot distances. If your a tad clever you can now "draw ahead in time" your own approach to the shooting spot and then be sure to follow that planed rout's headings and speed's. When you arrive on the shoot spot you can make a couple of extra plots on the target just to be sure that he is STILL going the same speed and heading.

Corsair how exactly do you estimate the targets course? By eye or you do some kind of conversion with the bearing to target?

Use the fixed nomograph, vertical or horizontal.