Good question! The only calibre of naval artillery on Bismarck that was not locked in and were gravity-mounted were... The 15in guns. The secondaries were all locked in by plates or joints to keep them (the lighter guns) from either falling out by heavy seas or from jumping out when firing. They did the designing before they built it so everything was set in stone, more or less.
From what I understand, the Bismarck, after capsizing (loosing her turrets on or near the surface and having her stern and admiral's bridge blown off my hydrodynamical forces), did have an angled descent trajectory while staying relatively upright (after flipping back over after capsizing). That would explain why she was hard to find, she sank in one place, drifted underwater to another on her journey down, and finally sailed through the mud down the slope of the volcano she landed on to her final resting place. That would also explain the strewn out placement of the debris, besides the current of course. The heavier pieces (the turrets, the admiral's bridge, and the stern) would have gone almost straight down from their breaking spot (where Bismarck really sank) to the bottom (where they are now).
I agree with Bill, from what I saw from the Cameron footage were the turret tops almost completely submerged in sea floor mud. You can barely see the turrets, they appear in the rippled mud here and there. So the faces are almost completely covered. Another way I could see the turrets identified, is the number of stories they have, from what I understood some had more or less than others. Also if some more barrel was showing we could possibly determine which one was Dora(?), the one what had it's barrels split open from a hit, unless that happened to more than I saw in the paintings...
AND THE SEA SHALL GRANT EACH MAN NEW HOPE, AS SLEEP BRINGS DREAMS.