[I'm goin' down]

Originally Posted by karamazovnew

No, it's not like the PK. On german subs you can't input data into the TDC unless you turn off Autoupdate. Actually what Autoupdate does is to link the periscope movement with the bearing dial on the TDC. That dial is at the same time linked to the AOB, Inpact angle and Gyro dials. So:
Autopdate OFF: you can input data, but if you move the periscope nothing moves on the TDC
Autoupdate ON: You can't input data but if you move the periscope you'll see other dials turning as well, plus you'll hear a clicky noise.
One thing to note (and written in the tutorial) is that if you move the periscope while in the Autoupdate OFF mode, when you turn it ON again, the Bearing dial will simply jump to the real value but without updating the AOB dial, thus breaking the solution. So don't move your periscope in Autoupdate OFF mode... ever.

Thanks for that answer. It makes a lot of sense. If you do turn off auto update, I assume you have to recalulate range and Aob? That would seem to make sense. Speed was established the first time, so that is not affected.

Next issue. I am playing with map contacts enabled. The course of the ship in the sub school tutorial mission is noted on the target icon on the Nav Map. If map contacts are disabled, how to you establish course? ( In PTO, by comparison, you can use the 3D TDC radar mod to establish course via plotting the radar readings.)

Also, in the sub school tutorial mission I have not been able to get hydrophone readings on the target. Maybe this is a bug in the tutorial. I assume in missions, you can get bearings of targets from hydrophone readings. Is that correct?