Don't Turn Your Back on the Ocean — Janet Dawson

Beautiful Ariel Logan was last seen quarreling with her boyfriend outside a Monterey pub. Now she lies dead on a California beach. An autopsy reveals that Ariel's death is no accidental drowning, but a cold-blooded killing.
Vacationing private investigator Jeri Howard has more than professional interest in the case: Ariel's boyfriend, the prime murder suspect, is Jeri's rowdy cousin, Bobby Ravella. Despite Bobby's refusal to defend himself, Jeri believes in his innocence, and instinct tells her the murder is part of a far larger evil. To find the truth, Jeri goes fishing for a big one in deep and treacherous waters and discovers that Ariel's short life was not free from dark secrets....