Thanks TorpX...as Ralphie said..."Oh f-u-u-u-u-dge!" I suspected the rudder problem was a tough nut to crack, but hoped that someone with your skills might have been looking into it. Maybe the changes you made in ISP are "close enough"...at least reducing the drag and fixing the turning radius; eh? I have just started using ISP2.6 for TMO_RSRD and would be happy to share my thoughts on the new behavior of the "Silversides" after I get a patrol or two under my belt...if you want those thoughts, that is.
Sailor Steve...oh, three cheers if you do fix that annoying "Yes Sir" bugaboo. I think I would have had any helmsman keelhauled for answering a conning order that way. Even the OOD, or JOOD if he had the conn, and/or the Diving Officer, would never think of responding that way to the CO's instructions for a course change, speed change, etc.
I suspect the difficulty you will have in making such a fix, will be to determine whose order the voice is responding to. The game scenario seems to be always based on the player, as the CO, having the conn and/or the dive. So, the proper response from the helm/lee helm and/or planesmen would be to repeat the order and add "...aye Sir." But, the double-repeat that I'm hearing is indicative of the CO giving his instructions to the OOD/Diving Officer and those orders then being passed on to the helm/lee helm and/or planesmen. Makes it a more difficult problem to get it 100% accurate (notice I did NOT say "100% realistic").
Anyway, thanks for the comments and best of luck to ya'...