Lets say that there is a sub in zone B. i am in zone A and wish to get to zone C. can i travel through seazone B from A to get to C, with out combating the sub in seazone B? or can i not occupy the same seazone as my enemies ever?
Lets add some clarity to this.
You want to do a Combat Move from SZ A through SZ B to attack enemy fleet in SZ C.
The enemy has two submarines (SS) in SZ B.
You must stop and fight the enemy subs since the control that SZ when you enter it. This ends the Combat Move for your moving fleet.
All Combat Moves for the current player are done, now Combat occurs.
In SZ B the fleet of 300 BB, 200 CV and 400 FTR are attacked by the two SS in the Opening Fire Phase. Two hits occurs. The attacking player can choose to take the damage on his BBs and/or his CV but not his FTRs since SS can’t shoot at air units. If he chooses to take both hits on one BB, that BB will not be able to return fire because Opening Fire casualties happen before Normal Fire.
In normal Fire now happens. At the end of this any casualties taken on the SS go into effect.
Now the attacking fleet can chose to retreat or press the attack and the defending SS can chose to fight or submerge. If they submerge they return to the board and remain submerged until the end of the Non Combat Move for the attacking player.
Back to the fleet movements…
The rest of your fleet is in SZ A. The advance portion of your fleet has moved to SZ B in the Combat Movement phase and forced the enemy submarines to submerge. This changed the status of SZ B from hostile to friendly until the end of the Non Combat Movement phase when the enemy SS surfaces again.
Your remaining fleet in SZ A now moves (Non Combat) into SZ B but still can not move into SZ C because of the enemy ships there and it is now NonCombat Movement.
However, your TRAN that moved into SZ B in the NonCombat Move can move into SZ D (no hostile units) and offload into friendly territories adjacent to SZ D. This is important since those TRAN were not exposed to combat even though they are moving thorugh a SZ that contains an enemy SS.
Lets put some concrete details on this.
NOR is occupied by UK forces, SZ 3 is empty (UK killed the German SS there on his turn).
EC == 1 INF, 1 ARM, 2 FTR
SZ1 == 1 TRAN, 1 BB
SZ 2 == 2 SS
US Combat Move:
SZ1 BB -> SZ 2
EC 2 FTR -> SZ1, SZ 2
US Combat in SZ 2:
German 2SS opening fire both hit, US BB is only available casualty and is sunk.
US normal fire, BB is already gone, 2 FTR both miss.
German 2SS chose to submerge since they can’t fire at the 2FTR.
US NonCombat Move
SZ1 TRAN embarks INF/ARM form EC, -> SZ2 -> SZ3, disembarks INF/ARM to UK occupied NOR.
SZ2 2 FTR -> SZ3 , NOR.
Note that the US player should not have sent his BB into SZ 2 on the Combat Move. His FTR alone would have forced the SS to submerge allowing NonCombat Movement into and through SZ 2.
Also note that the German SS in SZ3 had to be sunk by UK earlier. If UK had only forced a submerge in his turn, the SS would be back on the surface for the US player turn, preventing movement into SZ 3 during the NonCombat Move.
Hope that was clear and I apologize if I have taken a simple question and addressed it well beyond what you needed to hear.