I noticed a little difference in the two entries. Have you tried this:
[Flotilla 2.Base 2]
ID= Corregidor Island
NameDisplayable= Corregidor Island, Philippines
Info= CorregidorIsland-Base-Info
ExternalBaseName=Corregidor Island
AvailabilityInterval= 1941-12-20, 1941-12-30
DepartureDescription1= 14470476, 1726386, 329.117 ; Enum of available points, choose one randomly each time a patrol is started
DepartureDescription2= 14470476, 1726386, 329.117
DepartureDescriptionOut1= 14449908, 1711216, 276.175903
I added the two lines based on the other entry.
I have no idea what they do and I'm not sure if those lines link to other files, but it may help out.
Good Luck!
ElCid97