Found this last year and went back for another scan and dive recently with much better conditions. First time I dove it visibility was about 3 feet.
Very heavy construction and probably weighs nearly a ton on dry land. I am mystified as to what it was. It appears to be almost upside down but I could be wrong. Sitting in about 47 feet and stands at least ten feet high into the water column even at an angle. How far down into the lake bed it is is impossible to say of course.
What it was and how it got about 500 feet offshore I do not know.
Pictures are screen shots off the GoPro video-not particularly good but that's the best I can do.
Ideas welcomed as to what this thing is.
https://youtu.be/1eZs8KJN3GI
Position:
Lat: 43 39.191N / 71 25.410W