drag visualisation
 

A one of a kind drag visualization.
https://digg.com/video/box-bounce-back-into-car

That's a cool video, I've seen similar when an SUV drove over a plastic bag sitting on the road and it got sucked into the wake and hung out around there for a few seconds.

Yeah. I'd like to see that. I also think it is cool how the turbulent nature of the wake area creates chaotic cycles that are not sustainable more than a few seconds. Like, the bag could not stay in the wake area for minutes, just seconds. The wake area is just not a stable place.

EDIT: This one is kinda regular-seeming in movement pattern, but that is probably just because the flap is anchored to the boat:
https://m.youtube.com/watch?v=38v51JvIv0A