Sea without a Shore(1996)
(The second book in the Moontide and Magic Rise series)
A novel by Sean Russell
Sent by the palace on a voyage halfway around the world, Tristam finds himself led by a mysterious white bird--which may be the ghost of his uncle's familiar--to a remote island in the middle of a vast ocean, where the natives have clearly been awaiting his coming. And it soon becomes all too obvious to Tristam that his course was set by no living man.
Used availability for Sean Russell's Sea without a Shore
February 1996 : USA Mass Market Paperback