Ripples on a pond. :) Emma & I had the same idea for her quilt.
I used free-motion quilting for this, and surprisingly it did not take long - even with going slow at the start. The hard part is maneuvering the quilt. Which is the hard part in all of it, I guess. :P There will be more, but this is the biggest patch, so I did it first, then I will put the rest (smaller ripples, some overlapping) in random spots. The only thing I would change is I got the center of this almost in the center of the quilt.
And yes - it;s one big spiral.
New Wave quilt pattern from OhFransson.