Valley of the Rays - Nicholas Harvey - Bog

If it looks like a duck, swims like a duck, and quacks like a duck, it might be a bird of prey...
An unassuming man coerces his way onto the island with AJ's involuntary assistance. Could he be as harmless as he seems, or capable of something far more sinister?
When AJ encounters a stranger on a suspicious boat after her morning dives, she finds herself caught in a bizarre game of cat and mouse while she leads an unlikely villain all over the island.
Book seven in the series thrusts AJ into a knife edge predicament where the wrong move will cost her the life of a loved one.
Each book can be read in series order, or as stand-alone novels.