Tides of Awakening

Dr. Nia Reeves has spent her life fighting for the ocean-and getting nothing in return. When her groundbreaking research is stolen by a male superior, she dives alone into the Mariana Trench in despair, searching for something she can't name.
She finds a Tidegate.
Transported to Cerulea-a breathtaking underwater kingdom powered by ancient magic-Nia discovers she's the Sapphire Heir, a prophesied savior born of both surface and sea. But Cerulea is dying. An ancient entity called the Abyssal is...