Beneath Blue Waves (en Inglés) - D.M. West

There are more than sharks lurking in the depths.

After a research dive searching for sharks goes horribly wrong, Doctor Marnie Williams expects her recovery in Townsville to be uneventful.

When Detective Daniel Miller is called out to a potential missing person, he expects it to be a simple enough case. But then more bodies start showing up and he never expected all the carnage to lead to a reunion with Marnie.

There is something in the water. It's hungry and doesn't care about their tumultuous past. People are dying and Marnie and Dan will have to learn how to work together if they're going to have any chance of finding out what lurks beneath blue waves...