This is such an amazing site for a history nerd like myself. I sometimes like to just pick through the lists of ships attacked and read the different entries.

One thing that has struck me, is that it seems like the there is a disproportionate rate of war survival among U-Boat Commanders (or at least those who sunk at least 1 ship) and what I have always heard as the exceedingly high casualty rate for the U-boat service as a whole (75% is what I've read, but I know casualty rate reporting can be deceiving) . I was just clicking through the list of ships attacked when I noticed this, so I tallied the next 20 individual Commanders listed as sinking a ship: 16 of 20 survived the war.That surprised me especially for the period, Oct-Dec 1943.

My questions are: Am a reading this right? Is this seeming trend an anomaly, or am I wrong about measuring it against the 75%; is that a faulty number? Could this be a function of competence, i.e. you are competent enough to sink a ship, you are more likely to avoid sinking? Did the navy tend to pull successful commanders for land service or training after a successful patrol? Any recommendations for some reading material that might discuss such issues, greatly appreciated.