Resuply Question?

[Herr Commandant]

G'day All. Can someone please tell me when you can use the re-supply option with the radio operator. Is it used when in port or can it be used out at sea:hmmm:!!!!!
Hopefully someone has used this with success & helpfull advise.
Good hunting to all :DL
Regards. H.C.

[THE_MASK]

I think you can only use it at the times when it is scripted into the campaign layers IE drumbeat . I might be wrong though .