"In Davy Jones' Locker" is a nautical phrase that refers to the bottom of the sea, where doomed ships and their crews are believed to rest. However, there are many synonyms that can be used in place of this phrase. These include "deep six," "the abyss," "ocean depths," "sunken graves," "watery tomb," "shipwrecked and lost," and "down among the fishes." Whether you're talking about lost treasure or lost souls, these synonyms can help you paint a vivid picture of the undersea world and all its secrets. So the next time you want to describe something as being lost beneath the waves, consider using one of these colorful alternatives.