I've used dry erase markers on my shower wall before... I have one of those pre-fab molded fiberglass showers and the back wall rarely gets wet. The marker wipes right off with the eraser.
I stopped using them in there because the smell of dry erase markers in the enclosed shower gave me a headache.
I stopped using them in there because the smell of dry erase markers in the enclosed shower gave me a headache.
But it can be done.