Definitely the 'coral'-like growth, and the reflective surfaces that have darkened don't feel intrinsically magical, but magic-touched. Wrath has been around dark water long enough (during the volcano) for us to say it's valid he'd be able to tell this is the same magical 'print,' though much more residual.

You can definitely loot whatever you want, just pay mind to the boat.......... collapsing in... especially if you go for a window. But you could maybe aim for a mirror?

The same kind of magic pulsing through the coral is strongest towards the root, but you'd have to go deep, deep, deep, deep down another few hours — risk business!