Hi Sir,

From my DCG CAMPAIGN INFORMATION (v3.21, compiled by Tailspin)

All locations end in one of the following: "_Harbor", "_Sea", "_Ocean", "_Bay", "_Seaplane_Base†or “_Portâ€.
Note:  Any harbor can be an invasion point. Ports should act as both an unloading point for FRIENDLY units and a seaplane base.  But ENEMY units cannot unload at the port.

To be clear:
Seaplanes can take-off/land from/at "_Seaplane_Base" locations. TRUE or FALSE
Seaplanes can take-off/land from/at "_Port"                   locations. TRUE or FALSE
Seaplanes can take-off/land from/at "_Harbor"               locations. TRUE or FALSE

If the answer is TRUE, can I add:
the location "_Seaplane_Base" to the airfields.dcg file? YES or NOT
the location "_Port"                   to the airfields.dcg file? YES or NOT
the location "_Harbor"               to the airfields.dcg file? YES or NOT

Thanks Sir. Have a good day.
 

Seaplanes can take-off/land from/at "_Seaplane_Base" locations. TRUE
Seaplanes can take-off/land from/at "_Port"                   locations. TRUE
Seaplanes can take-off/land from/at "_Harbor"               locations. TRUE

 

the location "_Seaplane_Base" to the airfields.dcg file? YES
the location "_Port"                   to the airfields.dcg file?  You can try (I think yes)
the location "_Harbor"               to the airfields.dcg file?  You can try (I think yes)

Thanks Sir, have a good day.

Adding _Port and _Harbor to the airfields.dcg file works fine for both of them.

 

Thanks for all.

Good to know.