Davy Jones' Locker is a commonly used term for the bottom of the sea or the resting place of those lost at sea. There are several synonyms that can be used for this term, such as the abyss, the depths, the briny deep, the ocean floor, or the watery grave. Each of these alternatives carries a somber and melancholic tone, alluding to the tragic fate of sailors lost at sea. These phrases can be used interchangeably with Davy Jones' Locker to convey a sense of dread, loss, and finality associated with the mysterious depths of the ocean.