Hi Tom
Lock the target with the space bar.
Use the target identify icon from the gunner icon.
Press the E Key will show you the recognition manual.
Press the arrow on the recognition manual cover to shift through the different ship categories.
Press the manual cover to open it.
Use the red arrows to turn the pages.
When you see the target in the recognition manual send the mast height to the TDC.
You need to do this as you are going to use the stadimeter.
Press the E key again and it will all disappear, very useful if you need to use it again in a hurry.
Pause the game and place the periscope cross hair on the targets water line.
Press the stadimeter button that is on top of the range dial and bring it down to the top of the flag.
Press the enter Key.
Un-pause the game.
If you click on the range in the TDC you should see the mast height showing.
Try and take more than 1 stadimeter range so you get an accurate distance calculation.
You might find the navigator will also make some TDC calculations.
Peter