Subaquatic is a word used to describe anything that is beneath the water. It is commonly used to describe creatures found under the sea, but there are many other words that can be used in its place. Some synonyms for subaquatic include aquatic, marine, underwater, oceanic, and deep-sea. These words can all be used to describe the same type of environment, but they each have their own specific connotations. Aquatic is a more general term that can refer to both fresh and saltwater environments, while marine is specific to the ocean. Underwater suggests going below the surface of the water, and deep-sea specifically refers to the depths of the ocean.