Underwater crafts, also known as submersibles, are vehicles designed to operate underwater. Synonyms for these vessels include submarines, diving bells, remotely operated underwater vehicles (ROVs), underwater drones, and sub-aquatic vessels. These crafts are used for various purposes, including scientific research, exploration, military activities, and rescue missions. Submersibles can reach depths that are inaccessible to human divers, allowing for the exploration of vast and uncharted regions of the ocean. They are also used for underwater construction and maintenance of oil rigs and pipelines. Overall, underwater crafts are essential tools for understanding and preserving the mysterious and vast depths of our ocean.