James Cameron's Deepsea Challenge expedition (photos)

Weeks before the Deepsea Challenge expedition, which took place on March 25, crews prepared Deepsea Challenger for its first test in the ocean at Jervis Bay, south of Sydney, Australia. (Related article: James Cameron reaches ocean's deepest point.) (Mark Thiessen/National Geographic)

Explorer and filmmaker James Cameron emerges from the vehicle's hatch during testing of the submersible in Jervis Bay. (Related article: James Cameron reaches ocean's deepest point.) (Mark Thiessen/National Geographic)

Deepsea Challenger is lowered into the water for testing off the coast of Australia. (Related article: James Cameron reaches ocean's deepest point.) (Mark Thiessen/National Geographic)

Crews continue in-water testing in Australia of Deepsea.  (Related article: James Cameron reaches ocean's deepest point.) (Mark Thiessen/National Geographic)

After their successful nine-hour dive in January 1960 to the bottom of the Mariana Trench, Don Walsh and Jacques Piccard emerge from the bathyscaphe Trieste. (Related article: James Cameron reaches ocean's deepest point.) (Thomas J. Abercrombie)

Swinging above the docks in Guam’s Apra Harbor is the Trieste, the submersible that took Don Walsh and Jacques Piccard on the first and only successful manned dive to the bottom of the Mariana Trench. (Related article: James Cameron reaches ocean's deepest point.) (Thomas J. Abercrombie)

Jacques Piccard and Don Walsh emerge from the bathyscaphe Trieste following their successful manned descent to the bottom of the Mariana Trench in January 1960. (Related article: James Cameron reaches ocean's deepest point.) (Thomas J. Abercrombie)