PEARL HARBOR

On Dec. 7, 1941, Pvt. Joseph J. Ritson of Honolulu was getting ready for church when he heard a radio announcement that Pearl Harbor was under attack and that all military personnel should go to their stations. Private Ritson hastened to report to Schofield Barracks, a journey that was to be one of the most memorable of his life.

His first reaction to the report was disbelief, he says now. That feeling dissipated as he passed Tripler Hospital. ''The casualties had begun to come in and they had them lying on the lawn,'' he says. ''It was a sight - I was only 23 - that was just overwhelming.''

Ritson then headed down Kamehameha Highway to Hickam Air Force Base. ''They were flying over the top of my car. I was strafed from Hickam Field to the main gate of Pearl,'' he says. ''Everything was in flames. I could see the explosions from Battleship Row; it looked to me as if every ship in the fleet was going down.''

Ritson, who was a member of the 37-mm gun crew in the 298th Infantry, gathered with his convoy at Schofield and headed for his defense area. When he reached his position - near Kaneohe, on the windward side of the island - the attack was over. ''What we were preparing for was an invasion,'' he says.

Horrible rumors flew about all afternoon - that the water supply had been poisoned, for instance - and a terrible night followed; ''everybody was shooting at everyone else,'' Mr. Ritson relates. ''It was a difficult night to live. . . .''

You can hear him describe his memories of Pearl Harbor at the USS Arizona Memorial and National Park Service Visitor Center. He and three other volunteers from the Pearl Harbor Survivors Association have been speaking to visitors for the past four years. ''Since I have been out here I've talked to 900,000 people. This morning I've already talked to about 350 people,'' he says.

Pearl Harbor is now the only park with volunteers who are so personally connected with it; ''Custer State Park (in South Dakota) used to have a couple of Indians. Now we're the only ones left,'' Mr. Ritson says.

Pearl Harbor is Hawaii's most visited attraction, and even if you come early, there's a delay. While I waited for my group to be called, Frank Nalbach, my guide and a former World War II marine, took me to the rear of the center and pointed out across the narrow loch to thousands of roofs glinting silver in the sun, with the green, fog-shrouded hills beyond. ''You might wonder why there were no civilian casualties,'' he said. ''There were no housing developments here; it was all sugar-cane fields, right down to the waterfront.''

He waved his arm toward the far water's edge. ''Battleships were double tiered at the mooring keys - both destroyers and escorts.'' The Japanese planes came from over the hills beyond. ''They knocked out Wheeler (Air Force Base) first, then they (came here and) played ring-around-the-rosy for 2 hours and 5 minutes. They just had a field day,'' he said.

''The same quality of distance that makes Hawaii a peaceful place to vacation made people feel safe.''

The Park Service gives you a movie first and then takes you out on to the lanai, where you wait for the Navy vessel to take you to the Arizona Memorial. The movie consists mostly of old black and white newsreel footage: the Arizona taking Woodrow Wilson to the Paris Peace talks in 1918, the Arizona bringing veterans back from World War I, the Japanese Army invading Manchuria, the Japanese Army invading China. It ends with a long, horrifying battle scene, some of it re-created. All this is interspersed with underwater scenes of the Arizona as it is today, lying on the shallow bottom of Pearl Harbor, orange colored in the filtered green light and covered with barnacles; the accompaniment is a whispered recitation of the names of the men who died on her.

The crowd was mostly silent, but there was a faint gasp as the narration explained why the men of the Arizona weren't out and about the morning of Dec. 7 . The night before, the Arizona band had come in second in a ''Battle of the Bands'' competition, and the men were sleeping late as a reward.

Casualties on the Arizona accounted for almost half of the total deaths; almost 1,000 men were trapped below decks when the big ship went down.

You leave the movie theater and head out on to the lanai, where a Navy craft ferries you the short distance out to the Arizona memorial, a narrow, sugar-white structure poised across the ship's remains.

Of all the ships that were hit, only the Arizona, the Oklahoma, and the Utah could not be salvaged. It wasn't possible to remove the men from the Arizona; they are still there, considered to have been buried at sea.

The Arizona was cut off at the waterline; all that sticks above water is the neatly labeled No. 3 gun turret. You can look down for small brownish blobs of oil that ooze slowly up from the ship below; when the sun shines at the right angle there's a rainbow oil slick on the surface of the water.

The Arizona Memorial is a quiet place, the hordes of people notwithstanding. Some of that comes from the shape; it has a bleached-skeleton quality. A lot comes from knowing what lies underneath. People come to stare at the plaque ''dedicated to the eternal memory of our gallant ship mates who gave their lives in action in Dec. 1941,'' to snap pictur's of the long, long list of names in the chapel on one end, and to remark on how many of the same last names there are, to peer down at the ship - a vague brownish shape in the water - to listen to the loud snapping of the flag overhead.

Quite a few come over to Mark Hertig, the friendly park ranger stationed on the memorial, to ask questions. One rather grim-faced man, obviously old enough to remember the attack on Pearl Harbor, wanted to know which direction the Japanese planes came from.

Mr. Hertig explains to me that Pearl Harbor is one of America's great sites, on a par with the Statue of Liberty and Mt. Rushmore. ''Every one of these guys is one of America's heroes,'' he says.

The Park Service joined the US Navy in administering the site in 1980, around the same time the handsome new visitors center was built, and the Park Service is hard at work to elucidate Pearl Harbor for the visitor. ''We're starting to get old histories out of people,'' Hertig says. These would lend themselves to ''slide shows, all sorts of imaginative museum uses.''

The Park Service also plans to mark, on the memorial itself, exactly what lies beneath - which would be very helpful, as it is hard to picture at the moment.

In fact, I found the whole situation hard to picture, standing there in the brilliant sunshine, in the quiet, crowded with all the tourists in cameras and shorts, everything so calm and everyday. Nothing could seem further removed from a scene of bombs and smoke and flames. ''Don't forget,'' Hertig said when I mentioned this, ''for these guys who are down here, this was the last thing on their minds, too.''

While you are in the chapel, do what Mr. Hertig suggests and look for Paxton Turner Carter's name. His family has donated memorabilia which are now on display back at the visitors center. In a special glass case are Mr. Carter's medals and diplomas, his Purple Heart in its presentation box. Also some photos: one plainly personal, showing a round and sunny face, a real sweetie pie; in another, he is severe and martial in his new Navy uniform.

The visitors center is full of interesting things: old copies of the Honolulu Star-Bulletin, its front-page headline type getting larger and larger as you move along the wall, until the letters are the size of a hand. There is a photo of a local induction with all the volunteers wearing leis. One newspaper list of local war casualties reflects the multiracial nature of the islands, and Minoru Yoshimura took his place next to Robert B. Young.

There were a few old recruitment posters. For one, the artist had been plainly instructed to include all possible material inducements. It reads: Young men wanted for US Navy. Pay $17.60 to $77.00 per month, and allowances, board, lodging, medical attendance, and first outfit of uniform free.'' Another, which featured a small plane flying over a very blue ocean, says succinctly: ''Thrills.''

Hawaii was an especially romantic place in 1941. Waikiki had only three hotels. Bing Crosby burbling ''Blue Hawaii'' had been popular throughout the United States not long before. The Japanese pilots, heading for the islands, adjusted their course by listening to the gay, caressing sounds of Hawaiian music from a station they happened to pick up on their radios.

The more you look into the story of Pearl Harbor, the more horrifying ironies you see in it. It makes you shake your head thoughtfully as you leave, rejoicing to get back out to the palm trees and the sunshine.

Practical information:

The USS Arizona Memorial is open every day but Monday, from 8 to 3. At the moment, members of the Pearl Harbor Survivors Association are scheduled to speak to visitors every day but Sunday. Admission is free.

No children under 6 are permitted on the boat ride. Ticket availability is first come, first served. '' We turn people away as early as 12:30 in the summer ,'' says Mark Hertig.

Visitors must wear shirts and shoes; no bathing suits and bare feet allowed. Many companies offer Pearl Harbor cruises; however, these are tours of the Harbor only; they do not include stopping at the memorial or the visitors center.