His parents later divorced, and he was closer to his mother, who sent him to a school in upstate New York in 1932.

Image Dr. Munk, standing with his right side facing the camera, with colleagues preparing an instrument raft in 1952 near Eniwetok Atoll, the hydrogen bomb test site, where he monitored the ocean for a potential tsunami

After taking night classes at Columbia University, he decided to leave banking and gained admission to the California Institute of Technology, where he studied applied physics. While spending the summer of 1939 near a girlfriend in the oceanside community of La Jolla, part of San Diego, he landed a job with Scripps (now part of the University of California, San Diego), where he has worked most of his career.

Colleagues say Dr. Munk took advantage of emerging computer analysis tools to help turn his direct observations of the ocean into sophisticated research projects. But Dr. Munk says he is concerned that today’s young oceanographers rely too much on computers and fail to ask fundamental questions or take enough risks.

“Computers are a lot cheaper than boats, and a lot more comfortable,” he said. “And I’m a little worried about so many people doing computer experiments and losing their ability, the American leadership, in measurements at sea.”

His seafaring work includes some notable moments in world history. Days before nuclear tests were performed at Bikini Atoll in 1946, Dr. Munk and a colleague dropped dye in the water to assess how quickly radioactive materials would flush out of the lagoon.

Near the test site of the far more powerful hydrogen bomb on Eniwetok Atoll in 1952, he monitored the ocean for a potential tsunami. It did not happen, though Dr. Munk and his crew were doused by radioactive rain and had to toss their clothes overboard.

The high point of his career, as Dr. Munk calls it, came in 1991, when he traveled to Heard Island, a remote spot in the Southern Indian Ocean, to test long-range sound signals in the ocean.