Robert Duane Ballard is an American retired Navy officer and a professor of oceanography at the University of Rhode Island who is noted for his work in underwater archaeology and marine geology. He is best known by the general public for the discoveries of the wrecks of the RMS Titanic in 1985, the battleship Bismarck in 1989, and the aircraft carrier USS Yorktown in 1998. He discovered the wreck of John F. Kennedy's PT-109 in 2002 and visited Biuku Gasa and Eroni Kumana, who saved its crew.

Oceanography, also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the oceans. It is an Earth science, which covers a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and seabed geology; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers utilize to glean further knowledge of the world ocean, including astronomy, biology, chemistry, geography, geology, hydrology, meteorology and physics. Paleoceanography studies the history of the oceans in the geologic past. An oceanographer is a person who studies many matters concerned with oceans, including marine geology, physics, chemistry, and biology.