I've changed my opinion about a debris object being a wheel assembly.
My original post was in response to a post by Gregory Lee Daspit (referenced in my original post).
From the original viewing angle (I think taken from a trailer for the Discovery Channel broadcast) it sure looked like the debris was a wheel assembly.
But, when viewing the new HD video Ric posted from a different angle it doesn't look like a wheel assembly. A jpg is attached.
The top image in the jpg shows the location of the "wheel" at t=0.52 secs. The wheel object is flagged in the new Research Bulletin
Exploring the Debris Field as the upper right hand arrow.
The middle two images show an enlargement of the debris "wheel" and a photo of the real wheel posted by Gregory. I altered the color and sharpness to make it easier to see things.
The bottom image shows a different view of the "wheel" at t=1.19 secs. It's clear, at least to me, the tire is really made of up a couple independent rocks or pieces of coral.
Edit: I attached a second jpg (Not_a_Wheel_Explanation.jpg) showing what appears to be the rock/coral/sand components making up the wheel assembly.
My error - oops.
Having the video sure makes it easier to analyze what's in the images.
Does anyone know if there is a 'speedometer' in the ROV? If we knew the speed of the ROV it would allow a good estimate of scale since the image would sweep past the same linear distance independent of height. The problem with using some other reference object (like I did with a starfish) is that the estimated scale is only as good as the size estimate of the reference object and is only valid at that distance. Anything closer will measure too large; anything farther away will measure too small.
p.s., I really like the underwater contour maps in the Research Bulletin.