[kylania]

Originally Posted by Safe-Keeper

But I sincerely don't hope it means the campaign's not dynamic anymore.

It'll be dynamic as seen in this quote:

Subsim: Describe the campaign feature. Will SH4 have the same style dynamic campaign that was successful with SH3?

SH4 Dev Team: No, of course not. We’ll have a much better campaign this time. We’ll do this, among other methods, through more varied patrol objectives and constant interaction with COMSUBPAC and special events that serve to keep you on your toes even in the middle of nowhere.

Subsim: There are geographic aspects of the Pacific war that are distinctly different than the U-boats Atlantic war, such as numerous shoals and reefs, uncharted areas (marked on the maps as "dangerous ground", etc.), and countless islands. Describe how SH4 will capitalize on these areas.
SH4 Dev Team: You can’t have most of the special missions without wading in shallow waters, where there is not much room to dive into when trouble comes! The game will take players close to land on many occasions, especially, but not only, in the SUBSOWESPAC command area.

Now, the second answer isn't clear enough to tell if it'll be a full world map or just selected areas of the theater?