Two questions; Renown and Contact reports...
 

First of all, the easy one.

How much renown in GWX to make Korvettenkapitan?

Second: And more contentious....

I find the contact reporting mechanism extremely frustrating. Perhaps this is a bug, I don't know.

GWX, 90% realism. I was tracking this convoy, somewhere in BE. In easy range of the Luftwaffe. I snuck in with decks awash, and for some ridiculous reason, the game would not let me report this convoy's position. This is where I was, relative to the convoy. I have noticed that I have been able to send position reports based on the position of one escort, without a visual of any merchants.

http://i198.photobucket.com/albums/a...lipboard01.jpg

Can someone explain this? It seems like a bug of some kind....

Renown: more than 25,000 --as I've reached that and still a Kptlt.

With decks awash, maybe the game thinks you're submerged and won't allow you to use the radio?

I thought the radio could be used up to periscope depth ?

Only to receive messages not to send.
I think Brag is right. The game thinks you are submerged. Not sure though.
It's a strange thing when to be able to send contact reports and when not to.

As far as promotions are concerned check this thread http://www.subsim.com/radioroom/showthread.php?t=105724. The radio can be used up to 25m under the water. If you see the convoy but the game does not allow you to report it means that your crew has not "detect" it. To do this go to the hydrophone room (Key H) rotate the wheel yourself and identify the targets manually. Once you do that you will be able to send all the reports you like. It's a silly stock SH3 Bug I'm affraid, nothing to do with GWX