Info: This painting by M. Whelan was used as the front cover of the book "The Changeling Sea", written by Patricia McKillip, published 1988. This is what the book is about (text taken from back cover):

"Peri hated the sea that had taken her father and left her mother bemused in dreams. With her doubtful magic, she tried weaving hexes to keep the water from ever again stealing from the land. One night Prince Kir, who yearned for the sea, found Peri at her hexes and asked her to send a message from him. She cast it into the sea with her hexes. Then a sea-dragon hove up, bound by a chain of gold. When a magician changed the gold to flowers, the sea went wild, endangering the fishermen. And by night, the sea-dragon changed and came to land as a fair youth, strangely like Kir. Against the Sea-Queen's revenge for ancient betrayal, Peri seemed helpless. But something had to be done. And she meant to do it!"