From publisher blurb:
Welcome to the Singing Sea, an enchanting place of myth and magic to the west of Equestria’s shores. Legends tell that those who sail there sometimes hear delicate songs drifting up from the waters, telling of ancient feats from the days before Equestria.
These days, the Singing Sea is not so calm. Ancient magic seeps from places of power across the Singing Sea, creating strange phenomena such as the unending Everchill Mists or the sprawling Sea Forest in the east. It is across these waters that you must sail if you are to uncover the mysteries which await, and prevent a cataclysm that could affect every creature who calls the Singing Sea their home!