Crews aboard ships that you attack don't react to attacks... or sinkings. These guys even keep looking relaxed standing on deck and smoking in the midst of giant oil fires and at the bottom of the sea.
Should be an easy fix
Otherwise, lots of silly clipping/movement issues with crew members in the control room.
However I'm quite taken with just how stable this game seems overall. So far, oddly enough, all the real issues I found are just surface glitches, not truly broken code.