Open Seas: Just Add Water — Erik Schubach

There are many things that Marina, lieutenant in the US Coast Guard, doesn't know. Among them are exactly who, or what, she is. Her whole life she has hidden her abilities in water. Able to swim faster, dive deeper, and hold her breath for almost fifteen minutes at a time. The webbing on her hands and feet make her feel as if she was some sort of mermaid. She doesn't know how accurate that feeling is, until a mysterious and powerful woman comes calling, bringing the storm of the millennium to the Washington and Oregon coast. Marina is faced with a choice. Either join this woman she is convinced is evil, or let hundreds of thousands of people in the Pacific Northeast die.