When I saw this on side scan I knew what it was after finding the 1st paddle wheel stuck on edge in the mud like a donut. Obvious similarities. it might also be part of the 1st paddle whee. Can't tell.
This one is on its side and quite a distance from the first one.
Sorry about video quality. I'm having a hard time with YouTube-often once the file is uploaded something happens to the quality that I am trying to fix.
https://youtu.be/x7CuvI4dpYA