Sea-Duction, by Douglas Danielson
JAKE MORTENSEN’S best friend is threatened by a mysterious assassin—and now he’s scared and can’t remember who might want him dead. Meanwhile, Jake’s boss wants him to look into the disappearance of a beautiful young woman. Jake tracks her to the ultra-secret Hedonist Society, and discovers their actual program is more blackmail than entertainment.
To make matters worse, Jake is on the outs with his exotic Chinese-American girlfriend. And at the ocean, the monster surf is up—with an undercurrent that can kill you, if you let it.