The two ships sinking downwards!! The cable is in between them.
SPEAKER (FEMALE) (OFF):“The battleships are sinking towards the target.”
UrsusArctos: Battleships are not hydrodynamic underwater. Real-life battleships that sunk would disintegrate, turning over so that their gun turrets popped out, their superstructure came apart, and their bulkheads imploded from collapsing air pockets. But I can forgive Evangelion for not paying attention to any of that if the results are cool enough.
Alaska Slim: Actually, the upright issue aside, I don't think any of that is a given. Not in the time frame the episode presents anyway. When it comes to the turrets the Iowa-class had clips which could have kept the turrets inside their rings. There are cases of older American battleships designs having done so at Pearl Harbor.
Now would they have fired? Most likely not. Even if they had, the velocity would have been so low I think we would have been waiting for the proximity fuses to go off.