Water Spell by Lizzy Ford

A water mage and the protector she never wanted.

Rare water mage Sela is given no time to mourn the loss of her longtime protector and father figure before she’s faced with the one man standing in the way of her freedom: her new guardian, mage-warrior Tieran.
An Inlander with no honor, Tieran is loyal to no man, priest, king or god. If not for the magic binding him to the infuriating water mage, he would abandon her amidst the land-locked Inlands, away from the sea she yearns to visit, and pursue vengeance against those who killed his family.

Sela and her reluctant protector are soon thrown into the middle of a power struggle raging among the rulers of the four island kingdoms. To survive, both mage and warrior must overcome their distrust of one another, for the longer they resist their bond, the more perilous their journey becomes.