It's safe enough, but if you go on a boat trip up the Elbe, be prepared for the Germans doing Nazi salutes as you pass the old U-boats moored up at the sides! Honest.

One word on that.....don't try to photograph them.

uhm
actually don't... I took the boat tour a couple of times (school trips and the like) and I never saw anyone doing that salute,
My teachers would have raised hell,
heck I would have raised hell and told them off rather unfriendly for something like that ...
It might happen sometimes, but most times they get told off by someone ... or won't risk doing it. You can get into a lot of trouble for doing that, and I don't mean because of the other people on the boat, but real trouble with the police and judges ...