The relationship between the skin and the muscles can be described as

The skin is superficial to the muscle and the muscle is deep to the skin

This best describes the relationship between the skin and the muscles. The skin is superficial when it comes to muscle function and operation. And, the muscle is deep to the skin. It is below the skin, not attached to the skin, and does not serve to aid the skin in basic functions.

Abay where the river empties into the sea