The Ocean Between Us: A Greek Mythology Mermaid Romance (Hearts of Olympika Book 1) by Cate Rowan

Immortal mermaid Mareisa has suffered a thousand years in cursed exile. Shipwrecked Prince Kyros of Erion just crawled onto her deserted isle. These two survivors of the scheming Greek gods must first fight their unjust fates and then the attraction that sizzles between them. Little do they realize their love could shatter the dominion of the gods and alter the fate of all mortalkind…