Hi Rainer, thank you for that. While I have been looking through the U-boat sailings on various sites, there seems to be different thought on what is recorded as a war patrol sailings. When a boat sailed and reached its area and returned either due to lack of torpedoes or supplies is clearly a completed war patrol. When a boat returns early due to battle damage or illness after several days/weeks, then a patrol was recorded as being aborted/abandoned. However where the U-boat returned within one, two or a few days with mechanical problems then re-sailed after one or more days, I have noticed sometimes it is recorded as a patrol, and when it re-sailed a new patrol is listed, but others include the return date as the same patrol including within the new sailing date. Also when some boats first sail from a German port and call at a Norwegian port before continuing on in to the Atlantic, again the first sailing to a Norwegian port is sometimes recorded as a separate patrol, while others include it within the same patrol that continues on from Norway. Is there any set guide lines to help clarify a patrol from other type sailings?John p.s. I hope this makes sense.