The Ocean Fugue
The Fugue is never the same sea it was the last time it was travelled. Its waters are fickle and its currents varied.
Over the course of a year, it goes through several “phases.” Scholars have yet to devise a method of predicting which phase is next, but sailors have noted that, at the very least, it only shifts between four or five such phases, and the waters are calm for a week or two between them.
This ocean is only regularly travelled by those with large amounts of experience with her phases; other ships rarely make port where they intended.