The Isles of the Gods: Amie Kaufman

Magic, romance, and slumbering gods clash in the start of a riveting fantasy series spanning gangsters' dens, forgotten temples, and the high seas from the New York Times bestselling author of the Illuminae Files and the Aurora Cycle.
Selly has salt water in her veins. So when her father leaves her high and dry in the port of Kirkpool, she has no intention of riding out the winter at home while he sails to adventure in the north seas. But any plans to follow him are dashed when a handsome stranger with tell-tale magician's marks on his arms commandeers her ship under cover of darkness: He is Prince Leander of Alinor, and he needs to cross the Crescent Sea without detection so he can complete a ritual on the sacred Isles of the Gods.
Selly has no desire to escort a spoiled prince anywhere, and no time for his entitled demands or his good looks. But what starts as a leisure cruise will lead to acts of treason and sheer terror on the high seas, bringing two countries to the brink of war, two strangers closer than they ever thought possible and two dangerous gods stirring from centuries of slumber…