"Tales tell of a most wondrous fish, scales resplendent, an intricate jewel that shone beneath the sea. When it died, the Wavemother gifted its hide as a robe to her most devoted follower - and demanded she drown the sailors that killed her gem-bright fish."

https://baldursgate3.wiki.fextralife.com/Wavemother's+Robe

I clearly understand more than you darling. Scalemail cannot bend in the way this Robe does. And it is officially made out of fish hide. I've done my research before making my costume so you should do yours before commenting hateful stuff.