Under the Surface by N.R. Walker

When Hobart Detective Douglas Sawyer chases someone along Constitution Dock, the last thing he expects to see is the guy change shape and disappear into the freezing cold water. He also doesn’t expect a government suit to intervene on the case and offer him a job in a remote town in the wilds of the Southwest Coast to report on things that may or may not be weird.
As the leader of his consortium, Ciaran Brenner takes protecting his town of Tenebrae Cove, and his family, very seriously. He’s never been bothered by any cop who takes up post in town because none of them stay long enough to find out the truth.
Until Sawyer, that is.
Sawyer has never felt at home anywhere until he arrives in Tenebrae Cove, the creepy little town in Southwest Tasmania. He can’t explain the unnatural pull he feels toward the water, or to the man who seems to despise him. He knows things aren’t as they appear, not when it comes to the water and not when it comes to Ciaran Brenner either.

For reasons he can’t yet explain, he’s dying to get under the surface of both.