All last week mibsters from 11 states and the District of COlumbia shot it out at this seaside resort. Washingtonians battled Virginians. Virginians took aim against Marylanders. Marylanders tried to knock off Washingtonians.

Gangland slayings on the boardwalk? War between the states?

Nothing of the sort. It was the 55th Annual National Marbles Tournament, sponsored by the "Big Blue Marble" TV show, which attracted 54 mibsters - the marble shooters' term for themselves.

After four days of heated competition, the boy and girl national champs, an 13-year-old Pennsylvanians, were owned by the mayor of Wildwood, Dean Feinauer, of Reading and Diane Bertosh, of Pittsburgh, each received a $500 college scholarship from IT&T.

Although the metropolitan Washington area was well represented, the shooters didn't fare very well.None of them made it into the final rounds of competition, though they all said that they were enjoying their week in Wildwood.

Lisa Clayton, the 9-year-old D.C. girls runner-up, of 5338 B St. SE. asked if she was having a good week, replied: "Nope - yeah." "Well, which is it?" she was asked. She was enjoying the beach, but not the competition. "They're beating me," she complained.

Clayton, her arm around the waist of Vanita Morgan, 13, of 810 K St. NE. the District girls' champ, continued, "I like playing the games (on the boardwalk)," especially "skeeball."

Morgan was pleased about being away from home for a week. "I wish I could stay here," she said. "Me too!" pipe Clayton.

Vanita's brother Steve, 12, the District boys' runner-up, also attended the tournament. In one of the preliminary rounds against North Carolina's Terry Deese, Steve got upset when his shooter hit one of the center marbles, which slowly rolled toward the outside. It looked like the marble would stay inside the ring - and lose Morgan the point.

"You keep going," he said to the marble. "Whew," he exclaimed, shaking his head, "all right, it's about time," as the marble finally rolled out to score the point. Nonetheless, he lost the match to Deese - by one point.

Axandria 1977 and 1978 boys' champ Jerome Furman, 13, of 3826 Florence Dr., was 15th out of 37 going into the last day of the contest. After losing a match he sat on the sidelines with his head buried in his hands. He wasn't, as could be expected, very talkative, but he did admit that, except for shooting, he was having a good time in Wildwood. Also representing Alexandria was girls' champ Julie Gravette, 12, of 258 Burgess Ave.

This is the first year that Hyattsville has had marbles competitions. Sean Ganey, 12 of 4122 40th Place, the redheaded, Hyattsville boys' champ, said that the competition at the nationals was tougher than in Maryland. "They're better shooters here," he said. How much better? "A lot."

Kevin Zeigler, a staff leader with the Hyattsville recreation department, said that both Ganey and the Hyattsville girls' champ, Shirley Hoffman, 12, 3817 Hamilton St., have only been shooting for two months. They will be eligible for national competition for the next two year, he said, and that will give them a chance to improve.

"I heard the boy from Reading, Pa., practiced six hours a day for the past few months," said Zeigler. The Hyattsville kids were "not used to the exposure. I think they're doing quite well considering some of the other kids have been playing for a few years."

This is also Takoma Park's first year in the nationals. The city was represented by the brother-sister team of John, 10, and Carol Fotopoulos, 12, of 7700 Blair Rd, both of whom have been shooting for two years.

Four youngsters represented Cumberland, Md.; Beth Blankenship, 10; Jeff Kimmell, 10; Vance Ridgeley, 10, and Sharon Spitzer, 14. Darryl Fletcher, 12, represented Baltimore and Chris Carter, 11, represented Casanova, Va.

What the metropolitan youngsters lacked in success, they made up in spunk. Washington's Steve Morgan and Henry Frazier, 10, 240 W St. NW., rushed over to the judge's table after the announcement that the voting for "the best sport on the beach" was taking place. "Can you vote for yourself?" they asked, almost in unison.

Roger Howdyshell, the president of Marble King Inc., one of five marble manufacturers in the country, has attended the tournaments since 1968. "When I was a kid the country was coming out of the Depression and marbles were cheap," he said. "Give a kid a handful of marbles and he'd be busy for days. . . . I'll tell you: It's still there," he said of the game's popularity. "I've never seen a kid who didn't like marbles."

During the last day of the preliminaries, Richard Kauffman, assistant to the director of the Alexandria recreation department, announced over the public address system: "Any boy champion who has not yet had his picture taken . . ." "No, any boy, not just the champions," interrupted "Big Blue Marble" public relations man Steve Schechter. Kauffman, his microphone turned off, turned to Schechter and said, "Well, it doesn't matter. They're all champions, Steve. They're all champions."

Oka Hester, the tournament director since 1937, was asked why he comes every year.

"I don't know I never found out," Hester replied. "Psychiatrists tell you, (June is) the time of year you lose your mind."

Or your marbles.