What Sub Upgrades Are Possible?
 

This game seems to be lacking the various battery upgrades/engine upgrades or conning tower upgrades that SH3 did. If the game does offer upgrades What kind of upgrades are available for your sub? Are the only upgrades basicaly the same as offered on your first career patrol so the only way to upgrade is get a new boat, or is there another way. I'm trying to get upgrades for my boat so I can make it look like the historical USS Triton (SS-201)

http://www.rpadden.com/postcards/122SS201-Triton.jpg