This is a type of specific phobia that involves an irrational fear of the sea and all of its components, such as the ocean, large bodies of water, and aquatic creatures. People with thalassophobia may experience intense anxiety and panic when exposed to the sea, and may even avoid
From Wikipedia
Thalassophobia is the persistent and intense fear of deep bodies of water, such as the ocean, seas, or lakes. Though related, thalassophobia should not be confused with aquaphobia, which is classified as the fear of water itself. Thalassophobia can include fears of being in deep bodies of water, the vastness of the sea, sea waves, aquatic animals, and great distance from land.