I understand that there is now proof of the usual V-shaped wake angle not always being ~39 degrees depending on subsurface currents. I'm a bit confused about t

I understand that there is now proof of the usual V-shaped wake angle not always being ~39 degrees depending on subsurface currents. I'm a bit confused about the ring waves part of this article. How is the boat leaving a ring wave when it moves? Or is the boat just being lowered into the water to form a ripple? You can't tell this from the top-down view. For some reason, the way that the article was written made it seem that a boat moving through the water could leave an off-center ring wave wake, which makes no sense.