[CapnScurvy]

WH4K, a Porpoise class boat isn't really an upgrade over the Salmon. Actually the game lists it older by a couple of years (that's why you lost a couple of stern tubes).

Anyway, from what you tell us your last patrol was sometime at the end of January, 1943, so it's probably February '43 now. The game is suppose to offer it's first upgrade of SJ radar for a Porpoise class after July 5,1942. The next upgrade (to the SJ-1) is suppose to come June 30, 1943. I've heard the game has a problem in keeping up with this schedule, especially after a refit or boat swap, so I'm not at all sure what to make of that problem. How this "refit" problem may effect the issue I pointed out is not known. So the fix I thought you could try is just a guess.

The fact that you are using TMO 2.0 may throw a monkey wrench into what I said you could try. Ducimus changes a lot of things with his mod. For all I know the stock game dates (that I gave) of upgrades may be different than what's in TMO 2.0. What I do know is the entries found in the "UPCData" folder that I pointed out, are entries that I don't believe exist in the game. I've not seen any reference to them in the files that count. So again, its just a stab in the dark when I say try this.

You found the correct folders:
\silent hunters wolves of the pacific\Data\UPCData
\silent hunters wolves of the pacific\Data\UPCDataGE


Open the "UPCData" folder.

The "UPCDataGE" folder is the German counterpart (thus the addition of the GE tacked onto the name?) of the American side of things. If you opened the German "UPCDataGE/UPCDataUnits/UpgradePacks.upc" you would see quite a difference in file entries.

As I pointed out, delete the entries for both the Salmon and Porpoise class boats (since you've had to make a trade in boats) and see what you get. Again, how does TMO 2.0 affect this change, or how does this other issue of not getting upgrades when a transfer or refit takes place? I don't know. It really gets complicated now.