Louie Mathieson was taking his first tour of the battleship USS Oklahoma, his new home in that summer of 1940, when he heard voices drifting up through an open shaft.

“Hi, who’s down there?” the lanky 19-year-old sailor called into the abandoned ammunition hatch.

“We’re in the machine shop,” replied a muffled voice from the deck below.

Recently, at his home in Owls Head, Mathieson says that the next time he thought of that hatch was on the tumultuous morning of Dec. 7, 1941. It was through that narrow opening that he was able to lead several men to safety when their ship was bombed in Pearl Harbor.

Every fall since then, as December nears, Mathieson feels the pull of those nightmarish couple of hours when he was certain he would die. In 50 years, he has never been able to escape the familiar sadness of knowing that several of his good friends were among the 429 men of the Oklahoma who perished in those flaming, oily waters.

“When the feeling starts to grow in me, just around late November, I have to go out and talk to people about it. I talk to schoolkids, or a church group, or maybe a service club,” he says. “It gets me over the hump. It’s funny, but after that I’m clear for another year.”

His brother, Harry Mathieson, also was aboard the Oklahoma that day. Unlike Louie, though, Harry usually doesn’t care to publicly recount the horrors he experienced when he was trapped in the overturned ship.

“Harry is made of different stuff than me,” Louie says, turning to his shyer, younger brother, who lives in nearby Rockland. “This 50th anniversary is different. It’s a good time to talk about it.”

Louie Mathieson was working in a Civilian Conservation Corps woods camp 64 miles from his home in Minneapolis when Germany invaded Poland. Fearing that the Army would draft him as the war escalated, he returned to high school briefly and then enlisted in the Navy in May 1940. At Bremerton, Wash., he joined the 1,200-man crew of the Oklahoma.

In October 1940, the ship anchored off Honolulu as part of the naval buildup in the Pacific. A month later it tied up at Ford Island in Pearl Harbor, one of seven vessels in a vulnerable lineup known as “Battleship Row.”

Back in Minneapolis, 17-year-old Harry was hoping to escape the bitter winter and “get to a warm place.” Hawaii sounded ideal. He enlisted in the Navy and managed to get assigned to the Oklahoma. The pairing of brothers on a ship was not uncommon at the time. The Mathiesons, in fact, soon became good friends with the three Barber brothers, all of whom were killed at Pearl Harbor.

Louie had discovered the Red Front Cafe soon after arriving at Pearl Harbor. The popular hangout was run by two Japanese women named May and Lorraine. May made a point of knowing the names and hometowns of all the sailors who drank there, as well as the ships they were on. She could juggle as many conversations as there were sailors at the bar. Whenever Louie walked in, May knew what he wanted to talk about: his beloved snowy woods of Minnesota and his dreams of becoming a forester.

Louie played his favorite songs on the jukebox for May, and May introduced Louie to a song called “Maui Chimes.” It was the most beautiful Hawaiian song he had ever heard. They talked about the lush Hawaiian forests. When Louie went to sea on maneuvers, he left May with a prized photo album that was filled with pictures of him during his days in the Minnesota woods camp. They became friends.

One day, May invited Louie to sit with her and the other Japanese who always occupied the same back table at the Red Front. He was surprised, never having seen an American sitting there before.

“You don’t have bad feelings against the Japanese?” May asked him in front of the little group.

Louie said he did not, and thanked May and her friends for making his shore leaves so enjoyable. The conversation then turned to military matters: Was it true, May asked, that the Oklahoma had returned to Long Beach, Calif., for repairs of its drive shaft? Hadn’t it been in San Francisco recently? Who else was there?

The talk seemed too pointed; it lacked the lighthearted chattiness that Louie had always known at the cafe. He grew uneasy at the questions and said little.

Tensions were building in the Pacific by the fall of 1941. The crew of the Oklahoma began learning how to find their way with flashlights through the passageways of the darkened ship. Much of November was spent at target practice. Navy destroyers often had to nudge away Japanese fishing boats that began to circle the battleships on maneuvers. Despite the threat of war in that part of the world, however, Louie and the others felt safe in the haven of Pearl Harbor, floating on a ship built with 14-inch, armor-plated hull.

When Louie went ashore on Dec. 5, he noticed that the once easygoing atmosphere of shore leave had all but disappeared; people seemed edgier as they walked around town. Thinking his ship might soon be called into action somewhere, he got his photo album from May and took it to the Army-Navy YMCA to be mailed home that Sunday. He never saw the photos again.

On the night of Dec. 6, the Oklahoma was tied up beside the Maryland in Battleship Row. In the group were the California, the West Virginia, the Tennessee, the Nevada, and the Arizona. The Mathieson brothers both had the 4 a.m.-to-8 a.m. watch that next morning — Louie in the refrigeration plant, Harry in the evaporator room, both near the bottom of the ship. They asked to be relieved at 7:45 a.m. in order to have time to shower and get aboard the 8 o’clock liberty boat. When the watch ended, Louie and Harry left their clothes in lockers and met in the shower room, three decks up.

Just as Harry was about to step into the shower, and Louie was hanging his towel on a hook, an alarm rang throughout the ship. Bells clanged and the bugler blew his warning. The Mathiesons had been through several air-raid drills before, with American planes swooping around the ship in mock attacks. But considering that they both were standing there naked, and the liberty boat was leaving shortly, the brothers thought this drill was poorly timed indeed.

A deck officer then ran into the showers and screamed for them to get to battle stations. “This is it,” he yelled.

At that moment, Lt. Jinichi Goto, a flight leader for the first wave of Japanese “Kate” bombers, dropped to within 60 feet of the water and released his first torpedo. As the plane climbed back into the air, a huge waterspout rose beside the bow of the Oklahoma, marking a hit.

The ship shuddered from the explosion and dipped forward. Louie raced to battlestations at the machine shop while Harry went to the evaporator room. Louie, wearing nothing but a towel and shoes, was moving through the fo’c’sle when another explosion rocked the ship. His job at the moment was to close a 6-inch-thick armored hatch, but all he could think about was finding a pair of pants. When another torpedo struck, the deck he stood on rose more than a foot and threw him to the ground.

The tremendous pounding noises terrified him. His ears buzzed and his head seemed ready to burst from all the confusion and fear. He wanted to scream, to cry. He started saying The Lord’s Prayer to gain composure but was too frightened to recall the words. He tried the 23rd Psalm — “The Lord is my shepherd, I shall not want…” — when another torpedo hit. Louie grabbed for the nearest support, a drill press, and hung on. In desperation, he called out, “Lord, I place my life in your hands.”

The words calmed him, and he was able to join the others in trying to close the big armored hatch. But the ship was listing severely to port by then, and three men could not shut it. One of the sailors panicked.

“This is enough. I’m getting out of here,” he yelled as he ran for the door. Louie blocked his exit. He thought of knocking the man uncon scious, but he could not do it. He understood the fear.

The men pushed hard on an exit door, but had to let it slam shut when water began to rush in. They stood together in the machine shop, feeling helpless and confused as the damaged ship slowly continued to roll. That’s when Louie remembered the air shaft — the one he had seen open on that first day aboard. Could it possibly have been left open again? He climbed onto his friend’s shoulders and squeezed up into the darkened shaft. When he got to the top, his heart began to race. The hatch was open. He crawled out into the light and shouted for the others to follow. One man was too big to fit through the narrow shaft. Louie ran to find a rope to help him out but was stopped by an officer with a pistol, who ordered him to abandon ship.

On deck, Louie climbed a bulkhead and dove into the sea. As he hit the water, the huge ship groaned and rolled over. The tremendous wave force swept him more than 50 feet from the hull. When he surfaced, he saw a Japanese airplane bearing down on him. A line of bullets zipped through the water just inches away. Louie looked up at the approaching plane and waved to the pilot. The pilot did not wave back. When the plane got closer, Louie waved again. The pilot held up his hand as he streaked past, heading for another floating target.

Louie climbed onto a large life ring and watched a bomb slam into a turret on the West Virginia. The ship’s frantic crew instantly collapsed to the deck under a storm cloud of black smoke. Louie noticed heads popping up in the burning sea around him. Thick oil, pouring from the overturned Oklahoma, began to gush up from the sea bottom. By the time he was dragged into a lifeboat, Louie was vomiting black oil and wondering about his brother.

Harry had made it to the main deck area just as the ship rolled over. He and four other men found themselves huddled in a small room, shoulder deep in water. Their world had been turned upside down. They could recognize nothing. The men began to grope their way through the room, looking for any opening. Harry reached the butt of a 5-inch gun that he knew was always pointed out to sea. He pushed through a narrow passage and located the gun barrel under 20 feet of water. He swam along its length until he bumped into a web of thick ropes and had to go back. On his second try, Harry slipped past the ropes and swam for the surface until he thought his lungs would burst.

His face was so lathered with heavy oil that he could not see the daylight. He swam along blindly until he was pulled up into a lifeboat.

Released from sick bay, Harry began asking everyone about Louie. No one had seen him. He spent the night fighting fires aboard the West Virginia and the next day was sent to a submarine base in the harbor. There, standing on a dock, was his brother.

Louie was assigned to work in the harbor, picking up dead bodies and tending to the multiple horrors that the surprise attack had left in its wake. His will was gone, though, and he wanted no more of Pearl Harbor. Later, while escorting an aircraft carrier near Wake Island, he sung his prayers out over the Pacific.

While visiting Old Orchard Beach in the summer of 1942, Louie met Vera Payson of Owls Head. He courted her by mail and married her two years later. After serving on a battleship in North Africa, he finished the war back in the South Pacific and joined his wife in Maine.

Harry stayed in Pearl Harbor until 1943, patrolling the dangerous waters at night. After attending diesel school in the United States, he spent the rest of the war on a tug in Saipan.

The Mathieson brothers got out of the Navy in 1946. While visiting Louie in Maine, Harry met Eleanor Weed of Rockland and married her in 1960. They raised two daughters while Harry worked for New England Telephone.

Louie, a retired electrical contractor, had five children with Vera.

The brothers, both quiet men with a subtle hint of Minnesota still in their voices, have remained close over the years. But they have always differed in their feelings for the Japanese people and the effect that Pearl Harbor had on their lives. Louie will be in Hawaii on Dec. 7, to revisit in person the place he has has been compelled to revisit every year in spirit.

Harry has never felt the need to go back.

“I didn’t like it then and I don’t like it now,” he says. “I’ve never felt comfortable with the Japanese since that day. I have never made my peace with them. Maybe I will one day. I just don’t know.”

Louie’s day of reconciliation came in 1964, while at the New York World’s Fair with his family. At his children’s insistence, he grudgingly agreed to visit the Japanese Pavilion.

“I walked through with my back to the wall,” Louie recalls. “There were Japanese people all around me, and I really didn’t trust them. But by the time I left that day, I had finally made my peace.”