Origins of U.S. Submariner's Badge.
Some folks collect books.
Some folks collect badges and insignia. Some from each group will want books about badges and insignia, in this case submarine badges and insignia. In any event, whatever the size of the sub badge book gap in the fabric of space and time, Pete Prichard and Schiffer have filled it admirably. Now just in case some of you are getting the idea from the preceding that I'm a long-established expert in the field of sub badges, let me dissuade you from that notion. I couldn't, I have to admit, tell the difference between an authentic badge and a fake even if Admiral Hyman Rickover held a hauriant dolphin to the back of my head.