National Geographic


Expedition Journal

On Route to the Challenger Deep

After a full day preparing the ship, the sub, and the lander, we departed Guam late in the evening. The Mermaid Sapphire, with 60 souls on board, steamed out of the harbor, turned left, and took up a southwest heading. The smaller and slower survey ship, Barakuda, followed her an hour later. She was carrying 24 souls on board, including this writer, four scientists, and the lander team. The wind was blowing at 15 knots, and the waves were small, white-capped shadows of what they were two days ago.

Don Walsh is Jim’s special guest on the Mermaid Sapphire. The only living person to have dived the Challenger Deep is going back to the unmarked site in the western Pacific to see his old friend Jim climb into his new sub, close the hatch, dive through 7 miles (11 kilometers) of near-freezing water and explore the world’s deepest spot. It’s the exploration part that fascinates Don.

“We only had 20 minutes on the bottom before we had to go back up. The seas were building and we wanted to be on the surface before nightfall so there was no opportunity for scientific studies. From her push cores to her mechanical arm to her high definition 3-D cameras, DEEPSEA CHALLENGER is designed for deep-sea science. She has the hull shape and electronic stamina for a rapid descent to the bottom. ”

Walsh has an encyclopedic knowledge of the ocean and thousands of sea miles in military submarines, research subs, and surface ships. He’s been to Antarctica many times and circumnavigated the continent once. After serving in the Korean and Vietnam wars and commanding a submarine in the Pacific Fleet, he earned a Ph.D. in physical oceanography and became the dean of marine programs and professor of ocean engineering at the University of Southern California. His profound knowledge of ocean science and policy led to his appointment by Presidents Reagan and Carter to the U.S. Advisory Committee for the Oceans and Atmosphere. Walsh is a man of unlimited generosity. To spend time with him on the Mermaid Sapphire is to benefit from his wide-ranging knowledge of the ocean and his eagerness to share what he knows about deep-sea forces and the technologies and teamwork needed to work safely within their embrace.

“The military has small, elite teams like the Navy Seals,” he told me. “And large, specially trained teams like the officers and crew of a nuclear submarine. They have a shared culture and sense of mission that takes years to develop. The DEEPSEA CHALLENGE team is small, non-homogeneous, and rapidly building its culture and sense of mission. It’s made up of electrical engineers, mechanical experts, and life-support specialists, all of whom were hired for their technical skills.”

He paused for a moment. “Some members of the team have never been to sea before and yet the sub they are working on has made successful dives to 1,000, 4,000, and 8,000 meters. That’s pretty remarkable. They’ve been through some hard times and from what I’ve seen they’ve mastered the art of spontaneous collaboration and group resilience. But going to 11,000 meters will really test them.”

Don is right. He knows better than anyone that the forces of the hadal ocean can strip a sub to its bones and that the stresses of a seven-mile dive is the ultimate challenge for this team.


Written by Dr. Joe MacInnis

Photograph by Joe MacInnis

Science Partners

  • Additional major support provided by The Alfred P. Sloan Foundation
  • NASA Jet Propulsion Laboratory
  • Scripps Institution of Oceanography, UC San Diego
  • University of Hawaii at Manoa
  • University of Guam