Going home
Based on the belief in Pacific Northwest Coastal Native Americans that when one dies, they go down to the oceans bottom to await the ocra, or a killer whale, to take them to their underwater village. Once there, they become an orca and its also said that when an orca tries to flip a boat, they are trying to bring the living kin down with them.
Yes, that is another dead girl, though she would be more like a spirit them anything else.