[Sailor Steve]

When looking through the periscope or UZO, clicking on the Weapons Officer icon should give you a list of choices, including Torpedo Attack. There should be three buttons that come up with that choice. The left one should be Identify Target, the middle one should be Torpedo Aiming Data, and the right one should be Launch Torpedo.

Torpedo Aiming Data puts the information on the Notepad, and transmits it to the TDC. If that isn't happening, the nearest thing I can figure is that the GUI you're using removes the notepad. If that's the case, the WE Assistance isn't available to you.