What Is Thalassophobia?

The Fear of the Ocean and Other Deep Bodies of Water

Thalassophobia is the intense, persistent, and irrational fear (phobia) of large bodies of water, such as the ocean, sea, or large lakes. While thalassophobia is typically caused by a past traumatic event, such as a near-drowning experience or being frightened while swimming, other factors may contribute, including your upbringing, personality type, and even genetics.

Thalassophobia is derived from the Greek thalassa (meaning "the sea") and phobos (meaning "fear"). It is considered a specific phobia, meaning that panic, anxiety, and other negative symptoms are triggered by specific stimuli. Specific phobias are one of 11 anxiety disorders listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

Thalassophobia is not the same as aquaphobia which is the general fear of water.

This article looks at the symptoms, causes, and diagnosis of thalassophobia. It also discusses some of the treatment options and ways that phobias like thalassophobia can be prevented.

This photo contains content that some people may find graphic or disturbing.

Woman with goggles swimming below the surface in dark water
Deep water photographs like this may be troubling to people with thalassophobia.

Symptoms of Thalassophobia

Thalassophobia shares symptoms with other specific phobias, such as claustrophobia. The defining characteristic of thalassophobia is that these symptoms are triggered by exposure to or thoughts about deep bodies of water.

Everyone experiences thalassophobia differently. Some people might panic when swimming in deep water, being on a boat, or when unable to touch the bottom of a pool. Others experience fear just thinking about the ocean or when looking at pictures of deep water.

Symptoms of thalassophobia and other specific phobias can be both physical and emotional.

Physical Symptoms of Thalassophobia

While everyone's experience with thalassophobia is unique, there are some symptoms that are commonly felt. These include:

  • Shaking and trembling
  • Sweating
  • Dry mouth
  • Increased heart rate or heart palpitations
  • Difficulty breathing, including hyperventilating
  • Chest pain
  • Feeling faint, dizzy, or weak
  • Nausea or stomach cramps
  • Chills
  • Numbness or tingling in the hands

Emotional Symptoms of Thalassophobia

Thalassophobia can trigger a panic attack, which may induce symptoms such as:

  • Sudden onset of anxiety or fear
  • Fear of losing control or dying

Compared to many other specific phobias, thalassophobia may be dangerous. Drowning is a risk when experiencing a panic response while in deep water.

It might help to remember that the panic response is more dangerous than the water itself. If you know you have untreated thalassophobia, it can also help to always swim with another person or in the sight of a lifeguard.

Diagnosing Thalassophobia

Specific phobias, such as thalassophobia, can be diagnosed by your primary care provider. You can also get a diagnosis from a mental health professional such as a psychiatrist.

To diagnose thalassophobia, your healthcare provider may ask you questions about things like:

  • The specific fear
  • Avoidance behaviors
  • Persistence of the fear
  • Any life limitations that have resulted from the fear

DSM-5 Criteria for Thalassophobia

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes specific criteria for diagnosing specific phobias. To meet the DSM-5 criteria, a person must demonstrate:

  • Unreasonable, excessive, or disproportionate fear of a specific stimuli; In the case of thalassophobia, this would be fear of deep water
  • Consistent and immediate anxiety response when exposed to the feared stimuli (deep water)
  • Avoidance of the feared stimuli (deep water)
  • Persistence of fear for at least six months
  • Clinically significant distress or life impairment due to anxiety and avoidance behaviors

In previous editions of the DSM, a person also had to demonstrate insight that their fear was irrational, or disproportionate to the situation. As of 2013, this is no longer a diagnostic requirement. This means someone with thalassophobia might think their reaction is justified and sensible, even if it limits life activities or causes significant distress.

If you or a loved one are struggling with a phobia, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

Causes, Triggers, and Risk Factors for Thalassophobia

The causes of specific phobias are not well understood. They may differ from case to case. Some people may develop thalassophobia without a recognized trigger while others may develop the phobia following a traumatic event.

Nature and Nurture

Many researchers believe that specific phobias are caused by a combination of genetic and environmental factors. This means you may be genetically predisposed to a specific phobia, but it may not develop unless you have a traumatic experience or you are exposed to triggering events or ideas.


Research shows that certain genes are associated with certain specific phobias, but as of yet, no studies have looked at the genetics behind thalassophobia. However, there is still believed to be a genetic factor to phobias like thalassophobia, following the Darwinian theory of evolution.

Our ancestors were afraid of deep bodies of water, and it is likely that those who were cautious of the dangers of deep water may have lived longer to pass down their genes. This theory is supported by research that indicates that specific phobias are moderately heritable, although the exact percentage can vary. For example, it has been found that for specific animal phobias, heritability is around 45%.

Past Traumatic Events In or Around Water

Thalassophobia can also be caused by traumatic events. A childhood near-drowning experience, witnessing a shark attack, never learning to swim, or even being told scary stories of the ocean are just a few examples of possible events that could trigger thalassophobia.

By associating a specific situation, such as being in deep water, with a panic response, a phobia of that situation can develop over time.


Some researchers believe that parental behavior may contribute to the development of specific phobias in children. Children who have overprotective parents may feel as if they have limited control over their environment. This can contribute to anxiety and the development of specific phobias.

A parent can also model their own fears to their children. For example, a person may develop thalassophobia because a parent openly expressed a fear of deep water.

Other Risk Factors

One or a combination of factors can put you at risk of developing a fear of deep water.

  • Family history: If someone in your family has a specific phobia, you're more likely to have one, too. This may be because of genetics, or because of exposure to the person with the phobia.
  • Personality type: People who develop specific phobias tend to be sensitive and more prone to anxiety. They may be unwilling to take risks or may have a more negative attitude in general. 
  • Other traumatic experiences: Having a traumatic experience of any kind can make a person disproportionately concerned about danger and more prone to developing specific phobias.
  • Hearing about traumatic events around water: Knowing someone who died in deep water or experienced a traumatic event in deep water may trigger thalassophobia.

Thalassophobia Triggers

Thalassophobia triggers can include:

  • Ocean
  • Pools
  • Lakes
  • Boating
  • Swimming
  • Photos of deep water
  • Not being able to touch the bottom when in water
  • Movies featuring themes of deep water, such as Jaws

Treatments for Thalassophobia

Left untreated, thalassophobia can greatly limit a person's life. A person with thalassophobia may feel increased anxiety and quit engaging in activities they once enjoyed, such as going to the beach with friends and family, boating, swimming, watching certain movies, etc.

Phobias are also highly treatable, though the treatment isn't always pleasant.

Unfortunately, only about 10% to 25% of people with a specific phobia seek treatment. Because treating a specific phobia often involves confronting the feared stimuli, many people with phobias may avoid seeking treatment.

Exposure Therapy

Exposure therapy is a popular and effective choice for treating specific phobias, including fear of the sea. This treatment involves exposing a person to their feared stimuli at increasing levels of intensity until fear extinction is reached.

For someone with thalassophobia, this might start with looking at photos of the sea. Later, the person might watch videos of the ocean or deep water. Eventually, the treatment will involve exposing the person to the ocean or a pool.

Through controlled exposure, the person learns that the feared stimulus is not dangerous. Once this happens, they can begin to associate it with more positive outcomes.

Both single-session and multiple-session exposure therapy can be effective at reducing symptoms of specific phobias.

Cognitive Behavioral Therapy (CBT)

Cognitive behavioral therapy (CBT) is a type of psychotherapy. It is effective at treating a variety of anxiety disorders, including specific phobias.

In CBT, a person learns insight into their own thought patterns and behavioral responses. Through this insight, they are able to alter their thoughts and subsequently change behaviors and feelings.

For specific phobias such as thalassophobia, CBT is often used as a complementary treatment in addition to exposure therapy. However, some people might prefer CBT to exposure therapy because it involves less initial distress.


In extreme cases, medication can be used to treat specific phobias. This is often done alongside other types of treatment, or for specific situations. For example, if you have thalassophobia and are going to be on a boat, you might take medication to treat your symptoms during the activity.

Some medications used for this purpose include:

  • Beta blockers: These medications are often helpful in preventing symptoms of anxiety such as trembling and a racing heart.
  • Sedatives: Benzodiazepines can help you relax in the presence of a triggering stimulus. Since these drugs can be addictive, they are not recommended for long-term treatment of specific phobia.

When to Seek Treatment

Thalassophobia can impact your quality of life. It may prevent you from socializing or engaging in recreational activities. If your symptoms are causing you great distress or isolation, it may be time to talk to your healthcare provider.

Complications of Thalassophobia

Thalassophobia can cause great distress while you are in the presence of certain triggers, but this may not be the only effect it has on your life. Long-term, untreated thalassophobia can also cause other kinds of mental health problems.

Panic Attacks

People with specific phobias may experience panic attacks. These panic attacks can be debilitating and potentially dangerous. Panic attacks related to thalassophobia in particular may be dangerous because having a panic attack in or near deep water can lead to drowning.


Research has found a strong link between specific phobias and the later development of other disorders such as generalized anxiety and major depression.

Loneliness and Isolation

People who have specific phobias may self-isolate in order to avoid triggering stimuli. If you have thalassophobia, you may avoid any social interaction that happens near water, such as pools or the beach. In extreme cases, you may avoid seeing movies that are set near water. This kind of avoidance can mean less social interaction, which can lead to loneliness and isolation.

Substance Misuse

Research has found that people with anxiety disorders like specific phobias may self-medicate with drugs or alcohol. 

Coping With Thalassophobia

Coping with thalassophobia can be challenging, but there are things you can do to help limit your reaction to triggering stimuli.

Breathing Exercises 

Sometimes it can help to focus on your breathing. If your thalassophobia is causing a panic attack, try lying on your back with your eyes closed. Breathe in and out slowly through your nose. Try to make each inhale and exhale last about six seconds. Continue until you feel more relaxed.

Progressive Muscle Relaxation (PMR) 

Progressive muscle relaxation involves tightening and relaxing your muscles, starting with your feet and moving up your body towards your head. 

Mindfulness Training 

Mindfulness is a thought practice that helps your brain slow down and focus on the present. When practicing mindfulness, you stop and consider how your body feels, what is happening in your mind, and what is happening around you. Mindfulness can help you overcome the fear you are experiencing in the moment and become more self-aware. 


Visualization may help some people overcome a specific phobia. While you are at home or in a place without triggering elements, try imagining yourself near deep water. When this visualization no longer makes you feel anxious, you can move on to imagining yourself swimming in deep water. When you combine this type of visualization with therapy, it may help you overcome your thalassophobia more quickly.


It is important to take care of your own needs while you are trying to overcome your thalassophobia. Try not to self-isolate. Make sure you have someone to talk to and consider joining a support group.

Preventing Thalassophobia

Specific phobias can't always be prevented, but it is possible to avoid some of the situations that might lead to their development.

Get Help

If you experience a traumatic event around deep water, if you frequently feel anxious around deep water, or if you feel like your avoidance of deep water is impacting your quality of life, it's a good idea to talk to your healthcare provider, a therapist, or a psychologist. Seeking early treatment before your symptoms become overwhelming can help prevent you from developing a debilitating phobia.

Model Behavior for Family

If you have children, try not to let them see you react negatively to deep water. Avoid overprotecting your children, too. Children may adopt the fears of their parents and may become anxious when parents are overprotective.


Thalassophobia is a specific phobia of deep water. Specific phobias are irrational fears of specific stimuli that are disproportionate to the actual danger.

People with thalassophobia may have a panic attack when near deep water. In severe cases, a photo of the ocean or a swimming pool may be enough to trigger symptoms.

Thalassophobia can be treated with therapy. Treatment usually involves gradual exposure to the triggering stimulus.

A Word From Verywell

Specific phobias like thalassophobia are common and very treatable. If your fear of deep water is interfering with your quality of life, talk to your healthcare provider or a trusted friend or family member.

Exposing yourself to water, rather than avoiding it, can also help reduce your fears, especially if done under the guidance of a mental health professional.

Frequently Asked Questions

  • Why are some people afraid of deep water?

    Researchers don't know for sure what causes thalassophobia, fear of deep water, and other specific phobias. It may be a combination of genetics and environmental triggers, such as having a traumatic experience in or around deep water. Some people may develop thalassophobia by observing someone else with a fear of deep water, such as a parent.

  • Why is thalassophobia so scary?

    Thalassophobia can include both a fear of drowning in deep water and a fear of what might be lurking in deep water. The ocean and other large bodies of water are mysterious, and it's easy for people with thalassophobia to be overcome by its imagined dangers. When thalassophobia leads to panic attacks, the dangers of deep water can become very real because it can put you at risk of drowning if you're in water.

  • What is the difference between thalassophobia and fear of drowning?

    Fear of drowning is a feature of both thalassophobia and aquaphobia (fear of water). There is no specific phobia for fear of drowning, as it is considered a part of a larger fear. Both thalassophobia and aquaphobia can include other related fears. People with aquaphobia, for example, may also be afraid to drink water or take a shower.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Sarah Bence
Sarah Bence, OTR/L, is an occupational therapist and freelance writer. She specializes in a variety of health topics including mental health, dementia, celiac disease, and endometriosis.