Minoru Yamada thinks there is something rather beautiful -- poetic even -- about the location of the headquarters of JAMSTEC (Japan Marine Science and Technology Center) in Yokosuka, Kanagawa Prefecture. And this has nothing to do with being right beside the sea, with a great view across Tokyo Bay to the Boso Peninsula -- though many might think this reason enough.

"Look up behind us," he said, pointing inland. "On that hill there's a shell mound, one of the oldest and largest ever found in Japan. Excavated in Showa 25 (1950), it dates back 10,000 years." The most amazing discovery was a fishhook for catching perch. It was made of stag horn, which has no smell to warn off fish, suggesting Jomon culture was very intelligent; people then were on the cutting edge of marine technology.

"Now here's JAMSTEC, on the cutting edge in the 21st century," Yamada noted. "Cyclical, don't you think?" Ten thousand years ago, sea level was 40 meters lower than it is today and the continental shelf exposed. After the ice age, water levels and the temperature began to rise and are still rising, with tropical fish native to Okinawa increasingly seen around Hachijojima. In the Jomon period, 2000 B.C., JAMSTEC and both our homes were 10 meters higher and maybe farther inland than today.

Yamada dates his interest to when he was 5 and noticed crabs on Kamakura beach. (This by the way, is now much cleaner: "Raw sewage used to flow direct into the sea.") Growing up, he spent free time with his father exploring the shoreline, fishing and diving. Only in high school did the idea of an oceanic career gel. "I went to Nihon University to study fish culture. After graduating, I explored all kinds of diving research work -- free diving, scuba diving, saturation diving."

In 1970, Keidanren (the Japan Federation of Economic Operations) asked the government to establish JAMSTEC. Japan desperately needed a core research and development organization for marine science and technology development, it was argued. The sea is Earth's last frontier, covering 70 percent of the surface. Such an abundance could supply biological and mineral resources, also the possibility of clean energy through harnessing the power of waves.

Attached to JAMSTEC from day one in October 1972, Yamada has seen the facility grow by leaps and bounds. "We've 240 specialists in biology, seismology, geophysics, geology, chemistry and so on working here alone. This is JAMSTEC's headquarters, but we've branches in Tokyo, Yokohama and Mutsu."

One of the facility's first major projects was Seatopia, a major program that involved exploring the effects of saturation diving to 100 meters. "Four of us (all divers, all men) spent a month in this deep-sea submersible." He peered inside the vessel, massive in weight if not in size, now used by school students during summer camps on marine technology and ecology. "Yes, we had a toilet, also a shower. No, we didn't end up trying to strangle one another, though you would think so in so small a space. Too busy, I guess."

His wife, who works as a volunteer for UNESCO in Kamakura, used to worry herself sick about the saturation diving. What if he couldn't get back, what about long-term effects? But Yamada only feared the bends -- the terrible sickness caused by nitrogen bubbles forming in the blood when divers come up too fast. "You feel it first on your tongue, as if it's bubbling, then exploding."

He thinks there's relief all round that he's now behind a desk rather than at risk underwater. (He has a daughter at Keio University studying the viola, and a son studying nuclear science in Hiratsuka.) "But I was always a lot safer than divers of, say, a century ago, who wore metal helmets like this antique. Or boots. . . . Try to pick that one up." I couldn't.

Yamada wrote an international paper in the mid-1980s on open-water experimental diving to 60 meters, experimental saturation diving and the equipment used inside the chamber. It described the New Seatopia Project, aiming to sit 300 meters below the surface, and reviewed developments in diving watches, dry batteries, wet suits and equipment for health care. And concluded with the words of the Buddhist priest Butsugen, who sailed to Japan from China 700 years ago: "Zazen's not that dissimilar to deep-sea diving; both are silent."

Life has not all always been as deep. Once he and a colleague perfected the art of blowing bubbles under water. "It's not so different to blowing smoke rings. . . . Shaped like a doughnut, the rings spin rapidly and expand as they rise . . . and if two are produced side by side, they combine to form a larger ring." Designing a device that produced bubble rings automatically, the men foresaw applications galore. An American had the idea first in 1974, "but we transformed it into an art form."

Sounded fun, I said. Where could I buy one?

The EPCOT Center in Florida, he replied, chuckling.

Back in serious vein, his paper on a "hyperbaric aquarium" appeared in a book in 1990, "Spirit of Enterprise" (published by Buri International, Switzerland). "It's an annual collection describing research and new discoveries in all fields, sponsored by Rolex."

Yamada had designed and built a tank that enables fish to retain their natural equilibrium pressure when out of their natural habitat. "Fish have evolved to survive at different depths. Out of their depth, they become as distressed as we do, and can't live for long. My idea was to develop an aquarium for deep-sea fish, so that maybe we can culture and farm them in the future."

These days he works in JAMSTEC's public relations department, mostly concerned with education. Tuesday he had only color proofs and a mockup of two new CD-ROMs, sponsored by the Nippon Foundation; by today they are made and ready to use. Aimed at elementary school children, one is a general introduction to oceanic Earth; the second looks at the relationships among the ocean, living creatures and the Earth as a whole. "The project's for schools from Hokkaido to Okinawa. I'm really enjoying it."

He also teaches diving at public training centers. "Police, firefighters, you'd be surprised." Having worked over the years as far afield as off the coast of Mexico, he says he doesn't miss clambering in and out of wet suits any more. "It's very dark at 300 meters, and very very cold. I think it'll be a long time before human beings can live in any comfort underwater. The main problem is humidity. Human skin's naturally dry."

From the captain's deck of the research vessel Yokosuka, he pointed seaward. "See that floating dock? It's a 1-km-long experimental runway for aircraft to land at sea." JAMSTEC does all kinds of work, he added, leading the way through a maze of stairways and cabins. "Here (in this one) experts are mapping the ocean. This image shows an island in the Ogasawara group, 1,000 km south of Tokyo." Next door was a meeting room where two officials were . . . well, meeting.

Off duty, Yamada writes haiku and flies fighting kites. He began around 10 years ago, and for the last four or five has belonged to a group that competes in team kite-fighting events. It's where he gets his strong arm muscles from, he says -- the ones he needs these days in training, helping students pick up 1-ton boots for walkabouts on the "ocean floor" -- for which, read pools.

Next year will be JAMSTEC's 30th anniversary, and Minoru Yamada will be 57. He thinks it a good thing that people can learn about the organization's work. Maybe readers would like to come and look around, he suggested; there are tours at weekends, similar to the one he had just given me. I even got the official tour souvenir: a decompressed instant hot noodle pot -- you know, the indestructible polystyrene kind!

Funny to think of all those Cup Noodle containers trashed at the bottom of the ocean, shrunk in miniature. Nature doing its helpless best to resolve the garbage problem in the only way it knows how.