An increasing number of occupied submersibles are now employed around the world. For example, the American-built , operated by the Woods Hole Oceanographic Institution, is a three-person submarine that can dive to about and is equipped with a mechanical manipulator to collect bottom samples. Operated by the Woods Hole Oceanographic Institution, "Alvin" is designed to carry a crew of three people to depths of . The submarine is equipped with lights, cameras, computers, and highly maneuverable robotic arms for collecting samples in the darkness of the ocean's depths. "Alvin" made its first test dive in 1964, and has performed more than 3,000 dives to average depths of . "Alvin" has also been involved in a wide variety of research projects, such as one where giant tube worms were discovered on the Pacific Ocean floor near the Galápagos Islands.