von Zelda

You really haven't given enough information to completely diagnois the problem.

That said, I believe the most important factor in torpedo accuracy is target speed. If you are off by 1/2 knot or higher you stand to miss your aiming point. And the greater your target distance the greater the miss. It sounds like you consistently over estimate the target speed by 1/2 to 1 knot. You didn't state how you arrive at target speed but you might try dropping it back by 1/2 knot, then 1 knot and see what happens.

If it is not an error in target speed, then it is a problem with angle on the bow (AOB). I have found this to be the best way to compute angle on the bow. (1) On nav map, plot target course. (2) Plot your course on nav map which should cross target course. (3) Using angle tool, draw a line from sub to intersecting point of courses, and then place third point of angle at any point on target course in the direction of targets travel. (4) Note the angle. This is your AOB at that spot on the map and will never change unless the target changes course. (5) Go to periscope or UZO view and set the periscope or UZO view to 0 degrees. Then clear notepad of all information. Click angle on the Bow (AOB) and manually input the exact degrees you calculated in step #3, click the checkmark to go to the notepad view and then double click the checkmark to enter the value in the data computer. (6) You can now move the periscope or UZO in any direction and the correct AOB will be computed in the target data computer. This will only change if the target changes course. The sub can change course and the target data computer will correct for this. If the target begins to zig-zag, the original AOB will still be relatively accurate. The target is still travelling on the same true course, it just takes him a little bit longer to get there; thus target speed has been reduce but not by much; maybe a quarter to half a knot.

I hope this is helpful. It might be helpfull to use the Weapons Officer's assistance until you get a real good handle on what the target data computer is doing.

In real life, U-boat commander traning (if I recall correctly) required 90 surface torpedo attacks and 90 submerged torpedo attacks before being rated as a frontboot ready for war patrol.