[magic452]

I shoot vector shots all the time and never miss the way you describe.
If I understand you right, if you shoot on the 11° bearing you are missing aft of the target. Two things can cause this.

First are the doors open, I sure they are as your not new to the game.

Second If the TDC has old data in it you must set your scope to 0° and than pull down the range thingie all the way down, should give you a range of about 1400 yds. make sure you have selected the proper tube and than click the send range button TWICE. You can see the PK line up right with the second click. Use 180° for a stern shot, select a stern tube first.

Just setting the AoB to 0° is not enough. Also double check that speed is exactly 0 and the gyro angle offset on the PK is at 0.
I've miss one or two on the gyro offset thing.

I just dropped a 9000 ton troop ship at 3100+ yards and a 7000 freighter at 4200+ yards. All torps hit right on the numbers.

Another though, a good target course line helps but a 1200 yds that shouldn't be to critical but at longer ranges it is.

You sometimes have to allow for the target to change speed when she see the torp wake.
In good conditions this can be quit a bit of change, either speeding up or slowing down.
I usually force them to slow down by shooting right at or in front of the bow.

Hope this helps

Magic