[Checkmate King 2]

I have some questions regarding u-boats/milkcow re-supply.

What was the “normal” procedure for u-boats needing to re-supply?

Did they have any idea where they could locate Milk Cows?

Or were they “piece mailed” information, for security reasons, and were instructed by Bdu to proceed to a certain location & meet a certain u-boat or supply ship?

What was the procedure for the u-boats, if they couldn’t find their milk cow or re-supply ships?

Was there a procedure in place that would pre-define a minimum time frame for searching for the milk cow and/or supply ship and if not successful, then they go to “plan B”?

Did milk cows ever get resupplied at sea or did they normally re-supply at a port?

Thanks