Its official. Two campaigns will ship with the initial release of Cold Waters, one set in the mid-80's and another in 1968.
The '68 campaign features earlier versions of Skipjack, Permit and Sturgeon class submarines at a time when Soviet ASW forces are less developed but US boats still have to make do with WW2-vintage anti-ship torpedoes and the slow Mk37 anti-submarine torpedo.
It plays quite differently from the '84 campaign in that engagement ranges are significantly shorter, due to poorer sonar technology and the absence of towed arrays. The lack of missiles and wire-guided anti-ship torpedoes results in heavy reliance on torpedo salvos to take down surface ships.