Could you make a contact report submerged?

[MarkShot]

A question for you U-boat experts.

Playing AOD at the moment ...

Curious if U-boats could make contact reports while submerged? Was their a radio mast that could be used for this or did the boat need to be running on the surface?

Thanks.

[Bill Nichols]

U-boats could receive messages while at shallow depth, but could not transmit unless surfaced.

[cueceleches]

I think their radio antenna was an aerial going from the conning tower to the bow of the sub.