These phenomena can best be explained in terms of energy.
The sea is the symbol of the collective unconscious, because unfathomed depths lie concealed beneath its reflecting surface.
Those who stand behind, the shadowy personifications of the unconscious, have burst into the terra firma of consciousness like a flood.
Such invasions have something uncanny about them because they are irrational and incomprehensible to the person concerned.
They bring about a momentous alteration of his personality since they immediately constitute a painful personal secret which alienates and isolates him from his surroundings.
It is something that we “cannot tell anybody.” We are afraid of being accused of mental abnormality — not without reason, for much the same thing happens to lunatics.
Even so, it is a far cry from the intuitive perception of such an invasion to being inundated by it pathologically, though the layman does not realize this.
Isolation by a secret results as a rule in an animation of the psychic atmosphere, as a substitute for loss of contact with other people.
It causes an activation of the unconscious, and this produces something similar to the illusions and hallucinations that beset lonely wanderers in the desert, seafarers, and saints.
The mechanism of these phenomena can best be explained in terms of energy.
Our normal relations to objects in the world at large are maintained by a certain expenditure of energy.
If the relation to the object is cut off there is a “retention” of energy, which then creates an equivalent substitute.
For instance, just as persecution mania comes from a relationship poisoned by mistrust, so, as a substitute for the normal animation of the environment, an illusory reality rises up in which weird ghostly shadows flit about in place of people.
That is why primitive man has always believed that lonely and desolate places are haunted by “devils” and suchlike apparitions. ~Carl Jung, CW 12, Para 57
Carl Jung Depth Psychology Blog