Drowning in Him by Viola Masters

Connecting to the sea is one thing; taking a sea monster police chief as a lover is quite another.

Mara doesn’t know why she’s on the ferry to Monster Island, but she knows that a job is waiting. She goes through orientation, meets the local police chief, and is taken to her assignment and residence. She’s going to be a waitress.
Tyron has spent thousands of years waiting to find a human to act as mate. When he meets Mara, he senses that she has a lovely spirit with a longing for the water, but that’s it. Arabella identifies her as a likely candidate for Tyron, so he made sure to put her where he could find her at his restaurant.
On her day off, he gives her an invitation to the ball, but being uncharacteristically impatient, he proposes a date before the full moon.
Can a woman who can’t remember her past consider a future with a monster classified as ancient and terrible? Of course. At least she can see this monster coming. It’s purple.