If only I could understand what OKM are trying to tell me, Sailor Steve
Those message seems to first state that all Polish vessels can be engaged at the discretion of the Kaleun, but then later OKM starts talking about the Prize Regs... As you say, it was very confusing for the Kriegsmarine skippers in the early days of the war!
Re cruising with the merchantman -- will he not start weaving and trying to evade? I had to chase down a Tramp Steamer who was running flat out, and it was quite tricky to get alongside him and fire on him with my 20mm Flak
He kept weaving, trying to ram me while I was getting alongside. How on earth would you hit a target like that with an eel??