Everyone has fears, but some affect their mental health more than others. Are you afraid of being in or around large bodies of dark water? Does this fear of deep ocean and other vast, deep bodies of water prevent you from swimming or enjoying being even near the water? Phobia about deep water, known as thalassophobia, can have a negative impact on your quality of life.

The thalassophobia definition is pretty straightforward — it’s defined as the persistent fear of vast, deep, and often dark bodies of water that feel dangerous. Specifically, thalassophobia describes a person’s fear of the great unknown in the water right below their feet.

To better understand this phobia and to learn how to manage its symptoms, it’s helpful to gain a solid understanding of this anxiety disorder’s causes and treatment.

Signs and Symptoms of Thalassophobia

Unlike aquaphobia — which is the fear of any type or amount of water — thalassophobia is the persistent, intense fear of bodies of deep, usually dark, water and what exists below the surface. Whether in the deep sea, a deep river, a large lake, or any other deep body of water, fear can result from the thought of an unknown sea creature swimming below you, or even just from knowing how deep, expansive, and dark the water you’re in is.

For many people who have thalassophobia, the most frightening part is the idea that the water gets darker as it gets deeper. They also may fear the idea that they really don’t know much about the life forms that exist in the deepest depths. There are both physical and emotional symptoms someone with thalassophobia may experience.


Physical symptoms of thalassophobia can include:

  • Rapid heart rate
  • Trembling
  • Sweating
  • Shortness of breath or breathlessness
  • Abnormal breathing
  • Rapid breath
  • Dry mouth
  • Lightheadedness
  • Shaking
  • Butterflies in the stomach
  • Headache
  • Dizziness
  • Nausea
  • Chest pain or tightness in the chest
  • Confusion
  • Chills, hot flashes, or sweating


Emotional symptoms of thalassophobia can be just as disruptive and can include:

  • Dread
  • Avoiding being around large bodies of water
  • Panic
  • Having anxiety
  • Wanting to escape
  • Feeling overwhelmed
  • Extreme, intense, sudden fear or anxiety
  • Fearing a loss of control
  • Racing thoughts
  • Feeling detached
  • Inability to sleep

Symptoms can occur even when just looking at pictures or thinking of a watery expanse. The thought of being far away from land while in the water can be terrifying. In most cases, people who have this fear will be scared, nervous, and generally uneasy around any large body of water — it doesn’t have to just be the ocean.

What Triggers Thalassophobia?

Several things can trigger thalassophobia. Scenarios that might result in extreme fear and panic can include:

  • Lakes
  • Swimming pools
  • Boats
  • Scuba diving
  • Sea creatures — mythical or real
  • Submarines
  • Photos, movies, or TV shows about any of the above
  • Thinking about or anticipating having to be around any of the above

What Causes Thalassophobia?

Like many other phobias, thalassophobia hasn’t been extensively studied. As a result, researchers don’t know absolutely, but they believe there’s likely a combination of factors that can contribute to symptoms of thalassophobia. They may be related to genetics, past experiences, brain circuits, or upbringing that can result in an intense fear of deep ocean or other deep water.


Genetics can play a part in a number of phobias. Phobias are considered a type of anxiety disorder, which is often hereditary. Research has shown us that phobias can be linked to genetics.

Past experiences

Anytime you experience a traumatic event, for example something scary regarding or around water, the resulting fear may last well into adulthood and develop into a true phobia.

Brain circuits

Our brain is designed to react when we feel fear. When we experience a threat, whether it’s real or just perceived, our brain kicks into fight or flight mode. Anxiety disorders have been linked in studies to dysfunction in our brain circuits, which can result in certain phobias like thalassophobia.


People who grow up with anxiety-ridden family dynamics might be more prone to developing phobias. Fear can be something we learn. If a parent has an extreme fear of water or the ocean, it may be something a child picks up. That is, it wouldn’t be outlandish to think that a child might pick up on their parent’s anxiety and end up having a fear of deep ocean waters themself.

How to Cope with Thalassophobia

Although the fear may feel overwhelming at times, you can learn how to overcome a debilitating phobia like this. Coping with thalassophobia is possible with the right support.

“Thalassophobia can cause negative thoughts and feelings which can be targeted through cognitive behavioral therapy (CBT). CBT helps identify unrealistic thoughts that can be challenged and replaced with more positive, realistic ones.”

Talkspace therapist Bisma Anwar, LMHC

Both short- and long-term tools and techniques have been found successful in dealing with thalassophobia. Relaxation strategies like meditation, visualization, or deep breathing are all excellent ways to manage a fear of deep water.

The following have been found effective in coping with thalassophobia — and remember, the more you use these techniques, the stronger their impact can become.

  • Deep breathing: Deep breathing exercises are great because they’re something you can do anywhere. Take a deep, long breath, hold it, and then release slowly. Repeat this breathing technique until you start to physically feel your body soften and relax.
  • Visualization: Visualization is a way for your mind to help you face and conquer your fears. You could visualize successfully navigating deep waters without going into a panic. For best results, this might be something you want to practice with a therapist.
  • Progressive muscle relaxation (PMR): Progressive muscle relaxation is an easy-to-learn technique that can be extremely useful during high stress or high anxiety periods. It’s something that’s been found very useful for people who have panic attacks. PMR is an exercise where you increase and then release tension in targeted areas of your body. It can relieve mental or physical stress and help calm or quiet your mind.
  • Self-help exposure: Self-help exposure through visualization can help you confront many of your fears, including thalassophobia. Picture yourself close to a small body of water. Use any of the relaxation techniques you’ve learned to calm yourself. Then, slowly imagine yourself having more and more exposure to increasingly larger bodies of water. Eventually, you might find that your tolerance increases, and your fear subsides.


If you’re convinced or suspect that you’re dealing with thalassophobia, you might want to seek out an online test to determine if you do in fact have a fear of deep water. These tests are designed to help you explore how severe your symptoms are. You can also get a formal clinical diagnosis, too. You can reach out to your doctor, a therapist, or another mental healthcare professional to get advice and guidance.

Though there isn’t technically a formal test to diagnose thalassophobia, your doctor or therapist can help you understand more about your fear. A doctor can also rule out any other medical complications that might be contributing to your phobia. Once you’re diagnosed with a specific phobia like thalassophobia, you can begin treatment.

Treatment for Thalassophobia

If you’re living with thalassophobia, rest assured that it’s a treatable condition and can be managed. If you find your fear is getting in the way of experiencing life (such as you can’t or don’t want to get on a boat, swim in open water, or go to the beach because of the anxiety it causes you), it’s probably worth seeking mental health professional support.

Therapy for thalassophobia

Once you make the decision to get help for your condition, be prepared to be open about your current lifestyle and any past traumas with your therapist or doctor. The more open you are, the easier it will be for them to determine the origin of your phobia so you can work to heal.

The goal of your counseling sessions is to help you understand how your fear developed, identify your specific triggers, and learn to successfully manage any emotional and physical responses when they occur.

“Treatments for thalassophobia can include cognitive behavioral therapy (CBT) and exposure therapy. Each of these can help with decreasing the anxious thoughts and feelings that come up because of the fear.”

Talkspace therapist Bisma Anwar, LMHC

Cognitive behavioral therapy (CBT)

In addition to understanding your body’s response to thalassophobia, a therapist may also use a therapy technique known as cognitive behavioral therapy (CBT) — a form of psychotherapy (talk therapy) that modifies dysfunctional thoughts — to help replace your negative self-talk with more positive messages. CBT helps you control your thoughts instead of feeling overwhelmed by them. You may be given assignments to visit the ocean while remaining safely onshore to test some common coping mechanisms.

Exposure therapy

Exposure therapy is a type of CBT that’s commonly used to treat phobias like thalassophobia. This form of therapy mainly consists of gradual, repeated exposure to whatever you fear in a safe environment. The exposure allows you to manage and decrease your anxiety while redirecting avoidant behavior.

For example, if you have thalassophobia, you might fear the ocean. A therapist might use exposure therapy to work with you to overcome your fear by first having you think about a situation where you would be in the ocean. Then, they might move on to showing you images of the ocean. Finally, they might guide you through an in-person or virtual reality exposure experience of the ocean.

While there isn’t an exact record of how many people suffer from thalassophobia specifically, there are statistics on how many people experience a phobia of some kind: an estimated 9.1% of American adults report having a phobia in the last year.

While a persistent fear of vast, deep, and dark bodies of water can result in crippling anxiety symptoms, you absolutely can overcome your fear. Participating in therapy, whether it’s in-person or online therapy, will help you get one step closer towards overcoming your phobia. Whatever phobia you are dealing with, whether it’s thalassophobia, arachnophobia, thanatophobia, or claustrophobia, therapy can help you overcome it.

When you’re able to lessen the burden of a phobia and diminish its negative impact on your life, you’ll be able to spend less time living in avoidant fear. Instead, you’ll have a newfound perspective on the world and be able to prioritize living life to the fullest and enjoying each day. You might even decide it’s time to go back in the water!