Maelstrom (The Kinsman Chronicles‪)‬

Part 5 of Jill Williamson's Epic Fantasy Series The Kinsman Chronicles

When a plot to assassinate the king comes to Prince Wilek's attention, he does all he can to stop it, but in order to fight against the traitors' supernatural allies, Wilek must choose whether to take the easiest path or honor Arman.
 
Ravaged by hunger, thirst, and disease, the fleet becomes easy targets for unrelenting pirates. Despite these trials, rumors of land sets all sides on the same goal. Should one of Prince Wilek's enemies arrive first, what will it mean for the future of Armania?
 
Maelstrom is collected together with parts 4 and 6 in King's Blood.