Perhaps this might offer some more hints. On pulling into Lurker's Lorient, I saw that the German tanker had more normal reflections:
However, the 5 or 6 various other merchants in harbor had the white reflections. Here is a vivid contrast between the white ship reflection and the more normal reflections of waterside structures (especially the very nicely reflected bunkers!):
(FPS is not normally that low, but this Lorient is a bit intense, and very beautiful with PE3.)