Witch of the Demon Seas by Poul Anderson

When he came out on deck in the early morning, there was only a gray emptiness of waters out to the gray horizon. They must have left the whole Achaeran archipelago well behind them and be somewhere in the Zurian Sea now.

There was a smell of rain in the air, and the ship ran swiftly before a keening wind over long white-maned rollers. Corun let the tang of salt and moisture and kelp, the huge restless vista of bounding waves, the creak and thrum of the ship and the thundering surge of the ocean, swell luxuriously up within him, the simple animal joy of being at home. The sea was his home now, he realized vaguely; he had been on it so long that it was his natural environment -- his, as much as that of the laridae wheeling on white wings in the cloud-flying heavens.