Did anyone try the 1968 campaign yet? I am now playing this mostly and it is a lot of fun and very challenging.
US submarine weapons of the era were awful. You have the Mk 16, which is a WWII-era straight running torpedo, and the Mk 37. While the Mk 37 has an active/passive seeker and wire guidance, it is actually slower than most nuclear submarines! To have any chance of success, you have to get really close, preferably in the baffles of the enemy, and hit them before they can even react. This means there us usually a lot of stealthy maneuvering, often hair-raising close to the enemy, before you can take the shot. And if you blow your cover too soon and get counter-fired upon, at these close ranges you are in deep trouble. In 1968, sub-sub combat is very exciting stuff.