As President Carter rearranges the budgetary deck chairs on his ship of state, some of them are going over the side into the drink.

Which is to say that some federal programs will be revamped under Carter's new fiscal 1980 budget and others simply will be deep-sixed, deemed ready for a quiet but decent burial at sea.

One ticketed for dumping is the U.S. Travel Service (USTS), a little-known agency whose job is to entice foreigners into vacations in this country.

Carter wants to abolish the agency, transfer some of its functions to another part of the Department of Commerce and cut its budget from $14 million to $3 million.

No big deal, perhaps, but the USTS has important friends in high places -- namely the Senate and the House -- and they're already mounting a rescue mission for the agency.

Instead of cutting its budget and phasing it out, some members of Congress want to turn the USTS into a super agency of travel promotion and give it a budget of hundreds of millions of dollars to bring even bigger bucks home from foreign shores.

It's all a part of the traditional give-and-take between the White House and Congress, the struggle for control between the captain and others who want to get a hand on the tiller.

At USTS yesterday, where careers were hanging in the balance and jobs were threatened, the mood was lowkey, but collective fingers were being crossed in hope that the friends would have the final say.

The official word came down last weekend, when the president's budget plans were made known to USTS employes -- about half of the staff of 120 is based here, the others overseas.

"I laugh about it," said one official who didn't want his name used, "but there's not much we can do as employes. It's very delicate. It's unfortunate, but you have to abide by the administration's decision."

Up at the other end of Pennsylvania Avenue, however, Congress doesn't have to abide by the decision. Two of the more influential friends of USTS, Sens. Howard W. Cannon (D-Nev.) and Daniel K. Inouye (D-Hawaii), were fuming.

They first got word of Carter's plans for USTS late year. It came not from the White House, but from a leak at Commerce -- someone who broke the secret to them.

The two senators wrote to Carter, urging that he hold off until they could conduct hearings this year on the idea of strengthening USTS and intensifying this country's efforts to attract foreign visitors.

Meanwhile, former representatives Fred B. Rooney (D-Pa.) and Joe Skubitz (R-Kan.), neither of whom is in this new Congress, complained similarly, saying the administration should be doing more, not less, to bring in tourists.

Complaining letters were acknowledged by the White House, but the definitive answer came Monday morning, when the president formally revealed his into-the drink plan for USTS.

USTS and its friends cite rather impressive statistics to make the case for beefing up travel promotion programs: 20 million foreign "arrivals" in 1978 brought $8.6 billion into the United States.

According to USTS, a package tour-promotion program, through which the agency provided seed money to trip wholesalers, generated $400 million in tourist expenditures here and with U.S. airlines.

"The administration's feeling is that this is a job for the private sector," sais a USTA official. "They think tourism will go up anyway, with lower air fares and the falling dollar. Actually, we think this is the time to get up a really strong promotion effort."

Congress and Carter will somehow work that out, but meanwhile, they're wondering at USTS what to do about that big warehouse they have in Toronto.

"We've got millions of pieces of data, travel information and brochures from the states and cities to give out to Canadian traverlers who want to come here. I don't know what will happen to that," a spokesman said.