So Bismarck, being on the top of my favorite ship wrecks to study list, always seems to toss in a surprise or mystery every now and again when I'm studying wreck footage. Most of the debris is fairly easy to ID (more or less anyway) but I have to say, this one has had me completely stumped

. I cant tell if it's just a very awkward view of a turret tower, funnel section, or what. But it appears to be very square/rectangular in appearance. Anyone able to give a hint as to what this piece is?
https://www.youtube.com/watch?v=JzsRBD4MPO8