My first glimpse of the Yamato's wreck — through the acrylic sphere of my submersible — was her crest, the emperor's golden chrysanthemum, fixed high on the center of her bow.

This five-foot circle of golden flower, growing faintly out of the deep darkness, was the only recognizable, intact part of the great battleship that sank on April 7, 1945. The rest of her has been blown apart by every imaginable explosive violence — bombs, torpedoes, rockets, bullets, fires and magazine explosions Even the ocean joined in with pressure implosions as Yamato sank to the bottom of the sea.

In his recollections of that horrific day, survivor Mitsuru Yoshida described Yamato sinking at an extreme, 90-degree list. In that vertical position, he recalled:

"The shells for the main batteries fall over in the magazines, slide in the direction of their pointed ends, knock their fuses on the overhead, and explode. . . . At the instant Yamato, rolling over, turns belly up and plunges beneath the waves, she emits one great flash of light and sends a gigantic pillar of flames high into the dark sky. Armor plate, equipment, turrets, guns — all the pieces of the ship go flying off. Yamato's pillar of fire reaches...6,500 feet into the sky, its mushroom cloud rises to a height of...20,000 feet; sentries in Kagoshima, 220 kilometers north, report a flash of light."

Some bombs didn't explode as they hit Yamato, instead welding their steel tips into her decks. Two unexploded bombs, standing side by side at 20-degree angles, now form a part of the Yamato's wreck. Two feet long and 6 inches wide, the bombs are still filled with explosives and undetonated fuse; our submersibles gave them a wide berth as we moved past. Sailors' combat helmets are mixed in among the ship's steel, landing topside down when they floated down to the seabed.

From the maps that we were given, we expected to find Yamato intact from bow to stern. But what we found at the bottom was a wreck broken in two, like the Titanic.

The bow section of Yamato landed upright at a 45-degree angle, and the stern landed upside down. Its propellers and rudder are clearly visible — except for the outboard starboard propeller, which is buried vertically up to its blade depth in the seabed.

In this forest of twisted steel, a 25-foot length of propeller shaft rises from the seabed like a bent iron tree, two-and-a-half-feet thick. I couldn't help wondering if this tall, precariously leaning "tree" would fall in the sea slowly enough to allow our sub to slip away. I kept a cautious eye on it until we were safely out of its drop zone.

We looked for the Yamato's bridge, but we couldn't find it. It may lie under the overturned stern section, hidden from view, or it may have disintegrated in the explosions — pieces of the bridge are scattered everywhere. P.H., however, guesses that it probably lies further out in the debris field — perhaps somewhere southwest of the stern.

When it comes to shipwrecks, P.H. is a good and very experienced guesser. He joined the French navy back in 1964, as a young frogman trained for demolition and demining work. After more than 6,000 demolition dives, the navy transferred him into its new deep submersible program in 1978. In 1985, P.H. was again transferred into the navy's new scientific oceanographic institution, IFREMER, as director of deep-ocean submersibles. He has dived on ships that sank before Christ was born and ships that have recently foundered. Except for the Antarctic Sea, he has dived in every sea and ocean on our planet.

After a while, P.H. and I abandoned our search for the bridge and began looking for Yamato's huge three-gun turrets, each of which outweighed a naval destroyer. The ship's nine 18.1-inch guns have now vanished from her decks; as Yamato rolled over, they fell free and sank. One landed on the seabed just north of the outboard port propellers, touching the overturned stern hull. Another landed just north of the break in the bow hull. The third turret landed 230 feet south of the bow's number-one gun turret barbette.

As we surveyed the site, we noticed a small, beautiful, rectangular brass window. It was built to house 1-inch thick bulletproof glass, and though the glass is gone now, a few fragments remain. We recovered it for the museum, along with three 1-inch brass cartridge shells, a monstrous 4-inch shell, a lonesome shoe and a large, medicinal-looking brown bottle.

While we were measuring the wreck site, I was suddenly startled by a dark deep-ocean ray, as big as Jules and Jim, that glided in and nuzzled the sub's acrylic sphere only 5 inches from my shoulder. A large orange- and pearl-colored fish observed us grumpily from its steel cave behind Yamato's bowplate, and six feet away, a crab ran to the edge of Yamato's bow, jumped down and scurried to a hidden place. Sea life is much more active here than at Titanic, which lies so much deeper in the ocean.

Batteries flat, we finally headed home to the surface of the East China Sea, following P.H.'s rope highway all the way. Jules reached the surface first, followed 30 minutes later by Jim. We arrived well after dark, in a somber mood.

Our long day began with survivor Masami Hashimoto's blessing of the sea. It ended with the museum's Kenji Aihara cataloging the first Yamato artifacts — objects that will preserve the memory of Yamato and those who lost their lives when she went down.

The unforgettable journey in between was Mitsuru Yoshida's gift to me.