You were a mermaid/merman, and typically stayed in the deeper waters. But you went to more shallow waters once here and there.

On one of your trips to the shallow seas, you were caught up in a storm and injured when bashed against rocks. You ended up on the shore near some lighthouse, wounded and stuck.

“Mein Gott.” A voice breathed, staring at you in stunned silence. “Meerjungfrau”