Senior Week at Ocean City is all about testing the limits of a brand new high school diploma. Anything goes at "O.C.," along an incredible 10 miles of honky-tonk and hard rock--but just how far is another question.

Octave Pierre Jerome, a soccer standout from Eleanor Roosevelt High School, found out that it's okay to get close to nature in O.C., but if you sleep on the beach, you will wake up with a ticket in your pocket.

Mike Trapani, 18, a volunteer firefighter who just got out of Bishop McNamara High in District Heights, learned that no matter how much beer you drink while partying, you must remove your wallet before jumping into the ocean.

"Just say a lot of beer" was the way Trapani described the week to folks back home suffering city heat.

Several hundred of Prince George's 8,000 graduates were among the thousands of students who came from all over the state to stay the week ending yesterday. They have been coming to Ocean City following graduation as long as anyone there can remember.

The new men and women knew graduation meant more than drinking, although you had to look closely to tell. For a week they let the good times roll--a riotous ritual of youth pretending to look neither forward to the uncertainty and hard work of adulthood nor backward at a childhood now officially over.

"It must not be important," said Trapani of the soggy wallet, wading up from the surf to the AstroTurfed deck of the Best Western Motel, pulling the wallet out of his cutoffs.

He was staying at Best Western with about a dozen new Suitland High graduates. Also there was Volunteer Fire Company Number 26 from District Heights and some girls from Pittsburgh. The firefighters were there for a state convention. The girls, also recent grads, drove seven hours just to have a good time.

Trapani tried to wring his wallet like a washcloth, then flung it to a friend in a first-floor room, the 3 o'clock sun burning his back red.

At the other end of the boardwalk, Dave Winard, a fresh-faced Roosevelt grad who usually wore nothing but green gym shorts and sneakers, estimated that during his first two nights in Ocean City, parties of Prince George's students raged simultaneously "about every couple of blocks".

Ocean City is 145 blocks long. At night, the boardwalk was so thick with revelers cruising the bright lights and long shadows that it looked more like New York's 42nd Street than Worcester County.

In a rare moment alone on his third afternoon, leaning on the railing outside the room at the Boardwalk One Motel he shared with seven classmates, Winard stepped back from the party for a minute.

"You can see why kids stay in O.C. instead of Virginia Beach," he said, referring to Virginia's more strait-laced resort. "Kids are looking to do something they've never done."

"The summer is like the transition, the passage before going to work again. Especially the kids from Roosevelt," he continued.

Inside Boardwalk One, his roommates were gearing up for the evening festivities, which tended to start around 3 p.m. with a brew or two. Some were embarrassed while talking about the week and preferred to use nicknames. Six of the eight faced college in the fall. One was a National Merit scholar.

"You've just graduated. Now everyone says you have to change your whole way of life, but it's just not true," said Blade, a lanky 17-year-old from Beltsville.

Hope Jason, another roommate, was into sleeping when she wasn't partying, saying she preferred to let the party come to the room. James Miller from Glenarden, a sleek bodybuilder who never let a shirt spoil the view of his physique, was into "pulling," patrolling the boardwalk with Winard, hunting for girls.

"If you can't pull, you're useless," said Miller, one of a handful of blacks in O.C.

"The girls at O.C. act different than they act at home. They don't have to worry about parents, reputations or anything," Winard opined with authority. Not a hint of denial crossed the girls' faces.

Jerome jumped in with the story of the two girls that were hanging on the railing of a hotel near 13th Street the day before with a cardboard sign that read, "GUYS WANTED." He and Bagel Boy, another Roosevelt grad in the room, were going to take them up on the offer, "but we knew them from school," Jerome said.

"It's just crazy down here," said Dawn Costigan, 18, as she and others leaned over the balcony on First Street, checking out the continuous coming and going.

One person coming down First Street was a red-haired friend named Don who was thrown out of his hotel the night before because he had one too many guests. Then came Dennis Waby, 18, of Camp Springs, who was the extra guest. Tanned, hairy and amiable with a case of Red, White and Blue beer on his shoulder, he was an old friend the group had not seen for years, with a story to tell.

Waby said he was thrown out of Crossland High this year for drinking, was on the outs with his family and had just been put out of Don's Hotel. He came to Ocean City to be with his classmates for the party but decided to find a job with the carnival at the foot of the boardwalk. He was thinking about following the carnival to Florida in the fall.

"I just feel like a beach bum right now, but it's cool," Waby said.

The sun was beginning to set. Someone in the room was "collecting for brewskies," a cry heard up and down the beach at all hours. The nightly parade on "the boards" was at full march, past the Surf and Suds near Fourth Street, where a rock band was working and by the Brass Balls Cafe at 13th, where the firefighters had been in their steins since 2 p.m.

Girls wore shiny hot pants and striped halter tops. Guys donned floppy caps printed with the Budweiser logo and mirror-like aviator glasses with a thin, black head strap. Every time the white boardwalk train stopped, hotel guests cheered from balconies lined with beer cans and poured their toasts toward the sea.

Back at the Best Western, the volunteers from the District Heights fire company, who take their duties as firefighters seriously, were dancing in a circle near the small swimming pool with the Pittsburgh girls and a few of the kids from Suitland High School.

Later, to the beat of David Bowie's "Let's Dance," they would prance in the pool for a bit, clothing and all. Trapani had managed to go swimming with his wallet again.

Betty Constantino, 17, a former pompon at Suitland, was wearing his crimson McNamara jacket against the slight ocean chill. Her diet for the evening had been typical.

"We walked up the boardwalk for dinner--pizza and birch beer," she said. "I didn't pay, the guy that gave me the jacket did--I was shocked." Constantino works at Dart Drug and will study nursing this fall at the community college.

"I know some of these girls; they're great kids," said Helen Kulle, secretary of Fire Company Number 26, keeping a wary eye on the youthful festivities.

The Roosevelt kids at Boardwalk One were up until early the next day. After sleeping a few hours, they found their breakfasts between 9:30 a.m. and 1 p.m. Honey Nut-flavored Cheerios and milk was the fare for most. Dave Winard made Blade "one gross egg," she said, in the kitchenette. Two trash bags full of Bud bottles and cans already had been cleared.

Brad, a friend staying nearby, and Big Dave from College Park, were washing dishes. On the floor was a copy of a novel by Jack Kerouac and a book on Eastern religion belonging to another friend. Big Dave said his tastes ran more to Hemingway.

" 'The Sun Also Rises'--now that was a book!" said Big Dave, who always wore a calico cowboy handkerchief around his neck.

Bagel Boy and Jerome were already on their way up the boardwalk, to see about the girls with the cardboard sign, although they knew they were more than a day too late. Winard and Miller were out weightlifting, after a midnight ride in Winard's Mustang convertible with some girls from the Georgetown Visitation Preparatory School, whom everyone took to calling "the Catholic girls."

Betty Constantino wasn't sure what she had found at O.C., but she was being practical. She and Mike Trapani had renewed a friendship that had been lost when they left Francis Scott Key Junior High, when he was "a lot shorter" and she was covered with baby fat. She hoped, maybe, they would keep on talking when they returned to Prince George's.

"I'd like it to be so. I have his jacket, so he has to come and get it," she joked. "He says so, but I know men. This is Ocean City, not District Heights."