@ pocahontas. Hmm good point. Meena does in a sense drown, but she awakes as a siren, if that makes sense. Meena will be finding herself in a place to belong which she has always wanted. Ash has always thouht what he wants lives above the ocean. In a sense he loses himself in lusting after something and now has to find a way to get it back. Meena will probably be my main focus. Though I dont want to lose sight of Ash, either.
Sirens and their curse/gift will be a big sub-plot.
Soundless Waves and Drowning Lullaby are my choices. I suppose it depends who the single main focus is. The former makes me think of a mermaid where the latter makes me think of well...drowning, human. From what you've written it seems like Meena is the ultimate main character so I'd say the latter unless you plan to reveal about sea people in your summary!