Well this is kind of strange. On the DH full map, it seems literally impossible to invade either Balboa or Suez. The reason is that those provinces have beaches on the Panama and Suez canal, respectively, so that it is impossible to sail a fleet next to those provinces to invade them. What gives?
It gets even more annoying when you realize that these canal zones are worth VP so that you can literally never annex the controller of the canal zones, without first annexing a neighboring country.
The question arises why Balboa and Suez even have beaches, since it is impossible to do an Amphibious assault on them anyway.
Am I missing something?