In checking the stripes, these are in fact caused by the spine notches on the Bismarck.

I appreciate the help!

Also, I checked my 2 razors - in addition to the Bismarck, I have a square point Nate's Straight. Neither of them have a stabilizer, so I am going to monitor my reversing at the end of each lap to see if I am not reversing correctly as Bob points out.