A in-game problem

[mapuc]

By playing and testing I have noticed while submerged and pressing F5 or F6 I get the message surface the boat, while on surface I get the deck gun icon and the gun crew start to fire at the nearest target.

I have however still huge problems with my TDC-assistance

Ran into an English Tanker and used the TDC-range= 500, speed =0-I changed those setting and i missed of course-But as mentioned before I'm very bad at this TDC-thing.

Surfaced to shell it to destruction-The ship fired back at me-Had to submerged.

At periscope depth I used 5 torpedoes got two hit, one with TDC + manually changes and one by chance(not locked).

Surfaced again and used the deck gun for the last kill.

Some hours later I ran into another Merchant again I used my TDC-and noticed he gave me exactly the same solution as I had used against the tanker.

Is this some kind of a game failure ? A TDC that doesn't work
and is there a way to kick this XO and get a new guy ?

And how do i put myself into the seat of the deck gun ?

Markus