Water is the symbol for emotions and that which is in the unconscious mind.
The waves at the beach represent the way in which material from this hidden and mysterious place constantly interacts with our conscious mind as represented by land.
The undertow is a profound place where the interplay of simultaneous movement toward and away from the shore is dynamic and powerful.
It is the unseen force that can drag you away if you are not careful in your explorations of this potentially dangerous realm. It represents the fear of being overwhelmed by what is in your unconscious mind.Complete Dictionary of Dreams | Dr. Mıchael Lennox
To dream of noticing a strong undertow is an alert that you may be being sucked into a significant emotional drama. However, there is time to step back and not get caught up in another person’s boring choices.
To dream of being caught by an undertow and being out of control implies that you may now have to accept your part in an emotional drama before finding a way to breathe and walk away.Dream Symbols and Analysis | DreamForth
To dream of an undertow in the water symbolizes a strong influence that is working on you in your present life. You may feel “pulled down” by your current pressures, or by a particular problem or bad influence. You must use your self-control and willpower to assert yourself and regain control of your situation.My Dream Interpretation | myjellybean
Dreams of an undertow signify that you are feeling overwhelmed and out of control with emotions and passion. You may be venting out your fear of being seduced or unable to stand your ground in the face of a persuasive person.Strangest Dream Explanations | Dream Explanations - Anonymous
To dream of get- ting caught in an undertow is a sign that you will soon have to comfort a sorrow- ing friend or relation.The Complete Guide to Interpreting Your Dreams | Stearn Robinson - Tom Corbett