[hunter301]

While playing the training convoy mission again I noticed that the first two torpedoes I fired right off the bow without using any of the Attack Data Tool input went straight where I was looking. But then as soon as I brought up the Position Keeper and followed up the other shots they started going off in erratic locations no where near where I was aiming. What or when does the Periscope/torpedo combination actually get "slaved" to the TDC?
What is the purpose of the red button at the bottom of the Position Keeper for, Does it actually send the information from the Attack Data Tool to the TDC when you push the button and it turns red?

Is there some kind of training tutorials that can tell me what I'm doing wrong if anything? I don't want to go back to using the easy mode for shooting. Defeats the purpose of the game.