The Isles of the Gods by Amie Kaufman

Magic, romance, and slumbering gods clash in the start of a riveting fantasy series that spans gangsters’ dens, forgotten temples, and the high seas from the bestselling author of the Aurora Cycle and the Illuminae Files.

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 off to adventure. But any plans to follow him are dashed when a handsome stranger with tell-tale magician’s marks on his arm commandeers her ship. 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 stirring two dangerous gods from centuries of slumber…