The brigade of midshipmen marches off the Naval Academy's football field Saturday afternoon at 2:50 precisely.

Tom Bates, the school's sports information director, asked the new football coach, Gary Tranquill, "So when do you want to come on?"

"Two fifty-five," Tranquill said.

"How long do you need?" Bates said, meaning how long did Navy's players need to warm up.

"That depends on when we come out the second time," the coach said.

"I don't know that," Bates said, "because ABC hasn't told me yet. They did tell me the national anthem is at 3:42 and kickoff at 3:50."

The American Broadcasting Company will pay about $1.2 million to televise the Navy-Virginia game. For such loot, even honorable institutions such as the schools of Jimmy Carter and Thomas Jefferson will await word on when their football teams can warm up.

Every September, an aging sportswriter rummages through his garage in search of a soap box that once stood firm but now is rickety from the weight of years. On its rickety heights, he has declaimed loudly that college football ought to admit it is more show business than education. Admit it and then turn the school's teams professional. Pay the players. Let them go to class if they want to, but don't demand it. The truth shall set you free.

The good ol' boolah-boolah days are gone.

Frank Merriwell lies a-moldering in his grave.

Herschel Walker plays with a broken thumb.

For nearly $300 million, ABC-TV and CBS-TV bought college football rights for the next five years. According to Bo Coppedge, the Navy athletic director, a regional appearance pays each team $600,000-plus and a national show is worth $1.1 million.

Ted Turner pays near $400,000. "And I'm whizzed off that we're not eligible for Turner," Coppedge said, "but the rules say you can be on cable only if you weren't on one national or two regionals last year."

This has nothing to do with education.

This is show business.

This is professional football, except that the players are paid in pennies instead of thousands and are required to go to classes even if they need a rubber stamp to give autographs. Someday cities will own the National Football League teams, and egomaniacal millionaires will own college teams.

Because the University of Southern California was judged guilty of recruiting and academic abuses, it drew a two-year ban against TV appearances. But by a curious penal logic that would punish a bankrobber by sending him to jail a year after conviction, USC's plea-bargained sentence doesn't begin until '83. We can only guess as to how a bank robber would spend that year of waiting; USC will appear on television four times this season.

As part of this fall's package, Michigan at Notre Dame obviously is attractive. Scheduling of other games made it necessary to start the game at South Bend so late that darkness became a factor. Did this worry anyone? Would the descendants of the Gipper refuse to finish a game in the black chill of a northern night?

No, the sons of Rockne said, "We'll rent lights for the occasion." And so Notre Dame's stadium, without lights for decades, will rent portable lights for TV.

To accommodate Turner's cable-TV outfit, schools are renting lights at $85,000 a game. Mr. Jefferson's university at Charlottesville, where old times are not soon forgotten, has rented lights for two games. Virginia moved its Clemson game from 1:30 to 8 o'clock and moved Virginia Tech to Thanksgiving night, when the turkey might be frozen.

This is show business, folks.

Any doubts were removed last week when, on the cover of a slick magazine, there was a light-hearted George Welsh in a tuxedo. He was smiling and carrying a football on a silver tray.

Welsh coached at Navy for nine years. Here he was as fanciful as an anchor. But now he's at Virginia. Now he's in show business for real, with the tux and a smile. Over a telephone hookup at a press conference here today, Welsh even did a couple of one-liners.

Someone asked where his Virginia team is in its preparations for Navy, and Welsh said, "Midway between nowhere."

Is it true, a fellow asked facetiously, that Welsh planned to use Ralph Sampson as a split end inside the 20-yard line?

"No, tight end. He has bulked up," Welsh said, chuckling, "and he told me that if basketball doesn't work out, he wants to try football."

None of this show business much worries Tranquill or his boss, Coppedge. They have been places and seen things.

"I've been around long enough," said Tranquill, who was an assistant at Navy, Ohio State and West Virginia, "to know that sometimes education is not the No. 1 thing involved in a college football program. At the Naval Academy, more so than anyplace, education is No. 1. Football after football is very rare here. Philosophically, this is what I think college football ought to be -- education first, football second.

"Maybe there are circumstances where football is the tail that wags the dog. The money now is a reflection of the economy and it doesn't mean there's any more problems. It's up to the schools' administrations. If they insist they want football programs run the right way, as a coach I think it can be done."

Coppedge: "The necessity to be vigilant about corruption is damned important right now. The vigilance in academics is not where it should be everywhere. But let me ask you something. Is college athletics any more corrupt now than before television? I'd guess it's about the same. Before TV, whole states used football to advertise their state. With or without TV, these guys got their money from somewhere."