The Unknown Sea. Sea Mage Cycle

Getting his crew home safe will take everything this sea mage can give. As the youngest scion of a noble house in decline, Enoch knows that he'll have to make his own fortune, since he certainly won't inherit any. Fortunately, he was born with the gift of magic. The Peace of Caravelia has ushered in a new era of trade and prosperity in the Azure Sea, and after a few successful merchant voyages, he should be set for life.
But when an enchanted whirlpool seizes his ship during a battle with pirates, all those expectations are suddenly and violently shattered. When their ship emerges from the sorcerous maelstrom, the crew find themselves lost in an unknown sea. As ship's mage, it is Enoch's duty to see them safely through, but the lands they discover are not on any map, and the people they encounter are utterly foreign.
It will take everything Enoch has just to make sure they all make it back alive-if any of them return at all.