The video shows a person dressed in a mermaid costume swimming underwater. The costume is blue and has a tail that the person uses to propel themselves through the water. The person is seen swimming gracefully, moving their arms and legs in a way that mimics the movements of a real mermaid. The water is clear, and the sandy bottom of the ocean can be seen in the background. The person appears to be enjoying themselves as they swim around, exploring the underwater world.