I think you guys are right. I always thought it was some type of machinery but wasn't sure. On some spots (fishing in 27ft) I could drop a jig down with 7 or 8 ft of line and land on top of it. Move a foot to either side and the jig would just drop. Like it was the smoke stack or, top of the cab or something.

I wondered about grass or algea beds on that last one cause it looks like it only grows at a certain depth. When the hump or road drops off deep, the line of "grass" quits.

Now in the 2nd pic, that is in 20 something ft of water. Those would have to be some HUGE bucket teeth!! :D

That one still has me puzzled.

Anyway, cool to get others ideas and interpretations. I love this thing!