From: Hex 82,170
I played the CHS mod for WITP, and off map area for British forces coming into India made sense but, Panama didn't! I mean just have stuff show up on the west cost of the US/Canada a week later.
In the AE manual I see off map areas for the Soviet Union, Eastern Canada, Eastern US, Monbasa, Cap Town, Port Stanley, plus others. I just don't see the reason for most of these and forcing the player to moving troops, ships, supplies, etc. not only across the pacific but, also move them to/from all these other off map places seems like a bit. What the pacific map wasn't big enough, there wasn't enough already for the player to do? What is the purpose of these? What does this add to the game other than waste player time?
Andy mac has already given a lot of answers, but one of the main reasons for having the off-map bases is to provide a flexible way for the Allies to move forces between theatres (e.g. to/from the CBI, from other areas of the map) just as they had in Real Life. Firstly, movement "off" the map is done via the actual map edges, not bases near the map edges. This is more realistic. To provide the flexibility, there are off-map bases that are relatively close to each of the separate map edges. So TFs can move to these "nearby" off-map bases, then be moved to any one of the other map edges (via their "nearby" off-map bases) as the Allied player wishes.
For example, if the Allies wish to move ships to the US East coast for repair, then move them back to the map, then they can choose to send the TF to the US West Coast via Panama, then the Western map edge, or to the CBI via Cape Town, then the Eastern map edge. The existence of the Panama bases and the Cape Town base, apart from the reasons Andy Mac has given, also allow direct transfer between them, instead of having to travel to/from the US East coast. So that is another aspect of the flexibility. None of this flexibility would be possible if there were only, say, a US East coast base, and not the other ones.
I hope that makes some sort of sense?