Bloodfire Legacy. Sea Mage Cycle

A murdered wizard. A desperate thief. A daughter on the brink of damnation. Corin has never been a hero. A streetwise nobody and petty thief, he's survived this long by keeping his head down and his fingers quick. He can also hear the voices of the dead-whether or not he wants to. But when the ghost of the royal court magician begins to haunt him, all of that begins to change. His daughter has been dabbling in the dark arts, seeking to avenge his death.
In doing so, she has fallen in with the very people who killed him. Corin is the only one who can help him save his daughter. But to do that, Corin must turn from everything he knows and become something he's never been: a hero.