You can't do what you want with the replay, it's a thing Ubisoft added like you would put junk in you trash.
You must know the replay is intimely bound to your savegame.
In order to save a replay, you have to tick the "Save replay" check while saving your game.
Worst : You should do it for the entire patrol or won't be able to save replay if you load a game without replay saved. (so, stick with your 45 days replay info including 20 days of traveling east with nothing happens and 20 days of the same but westward
)
Also, controls in replays are barely existing :
You can hit F11 to get the free camera back to your sub (like ingame F11)
You can move and rotate the free camera on the three dimensions.
You can shift+click a ship/sub to have the view locked on it.
PERIOD.
And like I said previously in thread, you have to change gameplaysettings.cfg in the savegame to enable external camera, or you won't be able to press F11 and follow units.
I have suddenly an old thought about GTA4 replay editor, that was some serious sh*t. What Ubisoft gave us with SH4 is just what a poo would do if it was able to poop.
