Wave Rider by Eden Royale

When the daughter of a fisherman reels in the descendant of Poseidon, they learn some tides are too powerful to resist…

Kai is a merman shifter and descendant of Poseidon, Greek god of the oceans. Sworn to guard the tomb of an ancient evil, he spends his life ruling an empty kingdom beneath the waves. But when the daughter of his sworn enemy warms the coldness of his heart, he soon learns what it’s like to be a fish out of water…
Cora has always dreamed of exploring the ocean. Trouble is, the closest her father will let her get to the sea is mending his fishing net. But when she catches the attention of a dark and brooding sea god, she finds herself caught in his tide, with no way back to shore…
When an ancient evil invades the waters, both are forced to set bitter rivalries aside and work together to fight for the future of land and sea. And as the tides rise between them, they must choose whether to return to shore, or allow themselves to be swept away…