Mysteries with water themes:

A shark out of water : a John Thatcher mystery by Emma Lathen

Aunt Dimity and the deep blue sea by Nancy Atherton

Black water by T.J. MacGregor

Black water by T. Jefferson Parker

Catching water in a net by J.L. Abramo

A dance in deep water by Doug Allyn

Dark water : the strange beginnings of Sherlock Holmes by David Pirie

Dead dry by Sarah Andrews

Dead in the water by Dana Stabenow

Death by water : a Phryne Fisher mystery by Kerry Greenwood

Deep sea dead : a Pauline Sokol mystery by Lori Avocato

Don't drink the water [Large print] : an E.J. Pugh mystery by Susan Rogers Cooper

Fear death by water : a Harry Brock mystery by Kinley Roby

Fisherman's bend by Linda Greenlaw

Nervous water : a Brady Coyne novel by William G. Tapply

Ransom at sea by Fred Hunter

The shape of water by Andrea Camilleri ; translated by Stephen Sartarelli

Sun, sea and murder : an Inspector Alvarez mystery by Roderic Jeffries

Thicker than water by P.J. Parrish

Thicker than water : a Tori O'Shea mystery by Rett MacPherson

Too much of water by J. M. Gregson

The water clock by Jim Kelly

Water hazard by Don Dahler

The water lily cross : an English garden mystery by Anthony Eglin

Water of death by Paul Johnston

Have your own suggestions? Leave them in the comments for others to enjoy!