Diffraction pattern on the water

 I have blogged about these striped patterns on the water before. They look like the diffraction pattern from a single slit.

Today I got to see how they are formed. This stream near Great Orton goes over a very small bump at A. That's enough to create bubbles. The bubbles drift downstream and deflate. I wonder if it is a surface tension effect, perhaps hydrophobic or some such, that pulls them apart into rows. The spreading of the rows sideways will just be the fast flow slowing and broadening.