The USS Dolphin (AGSS-555) was a unique research submarine of the United States Navy, launched in 1968. It was designed for deep-diving research and testing, capable of operating at depths of over 1,800 feet. The submarine played a crucial role in underwater technology development and oceanographic studies. Throughout its service, the USS Dolphin conducted various missions, including testing new sonar systems and underwater vehicles. It was decommissioned in 2007 and is now preserved as a museum ship in San Diego, California, allowing visitors to learn about its contributions to naval research and exploration.