[He was a little wary, but the book he had read hadn't depicted the sea witch as particularly evil... she had helped the Mermaid, in her own way. He'll be friendly with her, so long as she was.]

Yeah, you sort of have to test things out to get the hang of it. I had a hard time too, since my essence was really only visible on land. You might have other abilities that work out of water, though.