Normal scratch marks from the anchor chain. When the chain is going in a downward/forward direction.

Now I see what you mean. I just saw the Swedish news clip from TV4. Those "scratch" marks are most likely from an anchor chain going aft, which it normally does not. Not in that angle.

This is from a slightly smaller vessel.

The chain stopper must be lifted manually and should normally be secured with a pin or similar. The brake(Gypsy wheel) should be tightened. The clutch can be engaged which will also lock the "Gypsy wheel". If all fail, the anchor will drop with an accelerating speed.

There is an object stuck to the hull. I'm not sure what it is. If it was welded to the hull in a hurry and the welding was not painted, it will leave rust marks beneath it. There is another one in the aft but they are only seen on the port side. See the SVT news clip for the aft one.

General Skobelev passed under the Great Belt bridge with two escorts. First looked like the Russian Corvette, no AIS, and the second was the Danish P523.