Another Way to Merge Visible

Question: is there a way to merge the visible layers, saving the result as a new layer and preserving the source layers?

Answer: yes. It's called Stamping.

Stamping layers makes it possible to merge the content of several visible layers into one new target layer.

You can either press Ctrl+Alt+Shift+E (easy for those without arthritis) or hold the Alt key down whilst choosing Merge Visible. Just remember that in doing this, you are adding file size.

Enjoy.