Just after dawn this morning, the stable keepers at the race track walked their horses down to the sea to bathe.They came down Bay Street past the old British colonial fortifications--St. Anne's Fort and the Garrison Savannah--then turned left on Aquatic Gap Street past the Holiday Inn to the sparkling white beach. There they could be seen, men and horses together, plunging into the calm coral waters beside the sleek cabin cruisers moored at the Barbados Yacht Club.

About the same time, and not far from the race track, U.S. Marine Corps Gunnery Sgt. Mike Kelly of Jacksonville, N.C., sat back and slung a leg over the second-floor railing of the Coconut Court Hotel, where he is billeted with other Marines, three to a room.

He lit a Camel and surveyed the street scene below. Birds chirped in the breadfruit trees. A score of joggers, black and white Barbadians--Bajans, they're called here--raced by.

Kelly took a drag on the Camel. "This ain't bad," he said.

The United States is once again at war in a tropical land, and this is the staging area. Three hundred years of British colonial rule prior to independence in 1966 shaped Barbados into a culture particularly welcoming to American tourists. They seem to shiver with pleasure when one of the locals says he will "nip 'round" somewhere.

Barbados is the land of the song "Island in the Sun," written by Irwin Burgie, of Bajan extraction, and made famous by singer Harry Belafonte:

Oh island in the sun/ Willed to me by my father's hand/ All my days I will sing in praise/ Of her forests, waters and shining sands.

Local tourist officials (tourism is the island's largest industry, with Americans the biggest single group) say there is no cause for concern: the war is 150 miles away across the open sea. Here, all is peaceful. The American troops seem to be behaving themselves, and while you can occasionally spot them in camouflage fatigues and boonie hats in the hotel lobbies, they are unarmed, quiet and watchful.

"They're not boozin' about," said deputy director of tourism Patricia Nehaul.

Troops and tourists, Brits and bikinis, officials and everyday working people in a sunny land on the edge of a war zone: Here are a few snapshots. The Sun Seekers

The American tourists are here in force, stretched out on the beaches, baking themselves in the hot sun. Tourist officials say there have been virtually no hotel reservation cancellations because of the war, except for an NASA group from Washington that had wanted to set up an exhibition in the old airport terminal outside town, which is being used by U.S. troops.

No one came, however, without checking first.

"Originally we tried to cancel, but they wouldn't cancel our reservation so we called our senator," said Dan Porter of North Dakota as he walked in his swimming trunks toward the ocean at Sam Lord's Castle, a major island resort. "He called the State Department and they said there were no problems, go ahead."

"It's been fine," said Lulu Porter, his wife.

"I wasn't worried," said Ron Whitehead, a power plant operator at the Grand Coulee plant in Washington State, as he and his wife Cheryl examined some seashell necklaces being offered by a vendor.

"We called the airlines," said Cheryl Whitehead.

"They said there were no problems on any of the islands except Grenada," said her husband. "I was really surprised at the people all lined up at the airport watching us get off the plane," he added, referring to the scores of people watching the big camouflaged U.S. military airplanes taking off.

Another couple, Gus and Mary Kramer of Cincinnati, said they checked with friends before making the trip. "I knew someone who vacations here at Sam Lord's and they said it's a long way from the airport, so we weren't worried that our pictures would be spoiled or our vacation be spoiled," said Mary Kramer.

"There were some people who said we're crazy," said her husband. "They said, 'What are you going down there for?' But I just thought it was overpublicized. Most people get driven off by the headlines."

As they spoke, a giant military plane flew low along the beach, gaining altitude, its engines roaring.

Sam Lord's Castle is a Marriott operation--isolated and lush on a craggy coral coast with white beach coves that look like every ad for a Caribbean vacation you ever saw. Named after a pirate said to have lured ships onto the rocks with lights at night, the old castle is a glorious Victorian mansion that looms huge and white, looking like the White House.

Double rooms run $225 U.S. a night--in the off-season. Many U.S. troops are billeted there but they were not in evidence on the beach yesterday.

At the Holiday Inn here in Bridgetown, Leann Belnap, who is vacationing with her husband, adjusted her bikini and said, "We were really leery about it; we gave it a lot of thought. We called the hotel, and they said everything was fine."

Belnap, sitting on a reclining chair on the sunny beach, said she thought the American action in Grenada was "great. I think we'd have a whole lot less problems if we had more people like Ronald Reagan." The Food

Three centuries of British rule did not entirely destroy the local culinary art. The specialty here is flying fish, usually deep-fried in oil like the fish you get at Long John Silver's.

The hotels also serve excellent cheeseburgers and french fries. Most people have that, downed with bottles of Banks, "The Beer of Barbados." The Locals

It seems virtually impossible to find a Bajan who opposes the U.S. action in Grenada.

When a local paper did a dozen random "man in the street" reaction interviews on the day of the invasion, Oct. 25, only one person was opposed and not on ideological grounds. It was an old woman, described as a pensioner, who said she objected because "my brain is unable to take such things."

Almost everyone here seems to think the invasion came just in time. Bajans say they are proud of their role in the joint military force as peacekeepers.

"I think it was the best thing that ever happened to Grenada," said a mechanic at a Mobil station deep in a rural area of sugar cane fields.

Several people having soft drinks at the station agreed.

"What the Americans have done is good," said Arthur Alleyne, a young man wearing a blue "NY" Yankees baseball cap. "If they allowed it to happen in Grenada, it would happen all through the West Indies."

As a reporter left the station, John Thompson, a grizzled man in a green hat, shouted, "Tell him that President Reagan should have been down here long before!"

"You might find the odd person who disagrees, but 95 percent of the people agree with it," said Charles Best, a waiter at Sam Lord's Castle.

"It would have happened to us as well--we don't want to be led by an army," put in another waiter, Richard Trotman.

Trotman said of the U.S. troops here, "They're gentlemen. They just come and go at the hotel."

A waitress, Collen Hayes, joked, "They haven't got any girls."

Everybody laughed. When a reporter approached the youthful group, they had been talking animatedly and approvingly about news that there were now 5,000 U.S. troops on Grenada.

The young workers joked about British Prime Minister Margaret Thatcher's reluctance to fully back the Americans.

"We feel if she had the first opportunity to invade, she'd be here," said Trotman.

"She wants to be recognized as the iron lady," said Haynes.

A bartender at the hotel, Delvin Gooding, said he had visited Grenada for several weeks earlier this year and was frightened by what he saw there. "I was so scared. All I was seeing was guns, guns, guns every day, everywhere. Soldiers with guns were just passing up and down the streets."

Like many Bajans interviewed, Gooding said the Oct. 17 assassination of Grenadan Prime Minister Maurice Bishop cemented his feelings that something had to be done. "They killed a good man, Bishop. People are really sorry," Gooding said.

Bishop, a Marxist, was assassinated by harder-line anti-American Marxists led by Gen. Hudson Austin who took over the government in a military coup. Austin was in turn deposed by the American invasion.

Desmond Bourne, a Bajan advertising executive, said of the invasion, "I'm glad. It's always an awful thing to find out one has cancer. But it's a good thing that our Caribbean community of doctors, with help of a master surgeon called the United States, is operating to restore normalcy and a healthy body politic."

Peter Odle, owner of a modest hotel called the Island Inn, is a Bajan with a Scottish wife, Patricia. As they raced to the airport yesterday to provide free orange juice and beer to the worldwide press corps gathered there, Odle explained his thinking.

"Most of the islanders are exceptionally happy, but some action was taken," said Odle. "But Grenada had not been a constant worry, because it seemed Bishop was becoming more moderate. He seemed to be moving toward general elections. But then something went wrong. From the time Bishop got shot, people became very concerned in this region."

Back at their hotel yesterday night, staff and guests gathered to watch television on the main patio, a breezy open room with faded latticework and creeping tropical plants.

Jamaican Prime Minister Edward Seaga was on the tube charging Thatcher with "shooting from the hip." Everybody laughed.

Then Grenadan journalist Allister Hughes came on, saying, "Thank God" for the Americans. "I don't regard it as an invasion. I regard it as a rescue operation." Everybody smiled broadly.

And then Cuban Ambassador Ivan C. Martinez appeared on screen, saying there were only five or six Cubans fighting in the hills of Grenada, not 500. Everybody groaned and laughed in derision.

"Oh, Jesus!" shouted a waiter. The Shuttle

American Airlines Flight 585 leaves New York's JFK Airport every morning at 8 and lands at Grantley Adams Field here four hours later. Because it is the first flight to land here from the United States every day, American 585 has become a kind of shuttle service to the war zone, especially for journalists.

They come aboard lugging heavy cases of camera equipment. It has taken many of them several minutes at the JFK security point to get their film and other equipment past the guards.

As the flight lets down over the sparkling Caribbean and the highly cultivated green, almost English landscape of Barbados with its neat little rows of red-roofed stucco and wood houses, the journalists press their noses to the windows to see.

A flight attendant goes up and down the aisles of the plane spraying a disinfectant, explaining that health officials require this procedure.

When you arrive at your hotel and open your closet, there is a roach as big as a fire truck. You know you are back in the tropics. The Brits

The members of a British bowling team checked into the Holiday Inn this morning. British tourists are everywhere. And some like it so much they come to stay.

"I'm not working," said Ann Bradnam, a secretary from England who said she quit her job and has enough money to stay here a year. "I just decided to sell up, move up and have a year off without work . . . I love it. The Bajans have always liked the British. They've always treated us well."

Bradnam, who was lounging on the beach at Sam Lord's, said she loves the nightlife in Barbados. "I always go to the Welcome Inn on Sunday nights. It's very nice there. They have Wendy Alleyne and the Dynamics."

Many of the well-to-do British stay at the Sandy Lane Hotel, an almost excessively luxurious hotel where double rooms in the off-season also go for U.S. $225 a night and where you walk down marble steps from a neo-Grecian veranda to the white beach and the sea.

Denis Atkins, a photographic salesman from Sussex, England, was sitting in his swimming trunks on a stone wall at the hotel yesterday, photographing the sun setting over the sea.

"I don't think many of us like to see aggression, to see people forced into a situation where they could become completely taken over," he said, "I certainly believe in democracy, you know, and I'm glad they've nipped it in the bud so to speak."

Another British subject, Andrea Bourne, was walking up the marble steps clad in a tight red string bikini, dripping wet. Asked her opinion of the Grenada invasion, she said, "To be honest, I haven't read much about it. But I suppose he's Reagan doing the right thing. I really haven't had much time to think about it."

Asked about Thatcher, she said, "Well, anything to help, I suppose," as she ran up the stairs. In Search of History

Geoff Scarrott, a retired Australian engineer, said he is here on vacation and is also researching a book he plans to write. A handsome man with gray hair, dressed in a khaki tropical suit, Scarrott said he is a descendant of Reynold Alleyne, who, he said, came here from Britain shortly after England settled Barbados in 1627. Scarrott said another ancestor of his directed the company that had a monopoly on the slave trade in these parts in the early 1700s.

Scarrott said his book, which will deal with these and other historical matters, will be called "All the World's a Stage." The Troops

At the bustling civilian air terminal yesterday, two young American Air Force enlisted men, both with tousled sandy hair, joked with each other as they waited for a telephone.

A black Bajan woman with her two small children approached them and asked politely, almost deferentially, "Are you Americans? We noticed your uniforms are different from the others."

The woman urged her well-dressed children forward for a closer look as the young men explained their ranks and service designations. The woman seemed delighted with this and the children were speechless with wonder. She bid the soldiers good luck as she left.

When she had disappeared into the crowd, one of the young men said to the other, "Wow, far out."

The U.S. troops here, perhaps several hundred in all, are friendly with the locals and sometimes even with the press. For the most part, young as they may be, these are professional soldiers, not draftees.

"No sir, not time off," said Army Spec. 4 John Cox of Griffin, Ga., as he sat with his comrades in a stone curb at the airport. Cox, who wore the jaunty maroon beret of the 82nd Airborne Division, camouflage fatigues and combat boots and who cradled his unloaded M16 rifle in his arms, said he was on duty all the time and was unable to enjoy the pleasures of Barbados.

Cox and the other troops seated near him don't get anywhere near the fancy beach hotels but bed down in blankets every night on the concrete floor of the old airport building.

"They got it easy," said another soldier about the troops staying in hotels. Cox and his companions have not been to Grenada but could be rotated in at any time.

Cox, with a 11-Bravo MOS (military occupational specialty), said he is a combat infantryman, or "grunt," as it was called in Vietnam and still is. He said he joined the Army because "I was tired of school. It was a change, let me mature some."

"He joined for the money, don't let him bull---- you," said another soldier who asked not to be identified. Cox said he makes about $500 a month before taxes.

Asked about the role of the press in this crisis, Cox said, "A lot of the press, they turn things around. They don't put the good stuff in. Lots of them, all they want is the negative things about the guys getting killed. They don't care about the good stuff we do."

A soldier who didn't want his name used said he heard there was a protest in New York against the American intervention in Grenada. "They should shoot those f------," he said, "The Russians wouldn't have any of that s--- going on."

"What they ought to do," said Cox, "they ought to let the congressmen step out of it and let the military handle it. Stuff would get done a lot better, a lot quicker. That's their job."

Pfc. Santiago of Jersey City, who would not give his first name, said he is 72-Whiskey, a petroleum supply specialist. Like the others, he wore battle gear and carried his M16. In addition he had a sheath knife strapped on his right calf just over the ankle--a special touch for Pfc. Santiago.

He's been in a year. "I had quit school, and the way New York and Jersey is, nobody can't get no jobs. It gave me a chance to make some money, travel--which I love, travel--and gain some respect from people back home."

Another nearby enlisted man said, "I'm not supposed to say anything, so I'm not gonna talk. I don't want to get in trouble."

Pfc. Destry Williams of Evergreen, Ala., 11-Bravo, said he joined because "I support my country . . . one reason is because my older brother was in the Army. He said it's a good start . . . all I'm looking forward to now is getting back home and seeing my kid."

Williams said he had been in since June. He said his brother eventually left the Army and is now a prison guard.

As these soldiers spoke under the broiling Caribbean sun you could hear the engines of the big military planes revving in the near distance.

Over at the civilian air terminal, a few hundred yards away, Army Sgt. Jesse Lee of Tallahassee, Fla., 62-Frank, a lifting and loading equipment operator, sat with several other soldiers around the busy food kiosks crowded with tourists and local citizens. The soldiers had no weapons.

"I joined the Army for a career," said Lee, who has been in 14 years and who served in Vietnam. He said he had no beef with reporters, "As long as the press doesn't put things in there to make our families more upset."

Spec. 4 Lori Douglas of Pittsburgh, 57-Hotel, a cargo handler, said she joined for "a career because the situation at home is no jobs, and it is a very good career. I like it."

She added wistfully, "I wish I could see the island Barbados ." Douglas said she and the others in her unit are living in tents near the airfield.

At the Coconut Court Hotel this morning, Marine Sgt. Mike Kelly, a helicopter mechanic with tattoos on his arms and wearing a white T-shirt, blue jeans and dark glasses, said he had been "around the world twice in both directions" in the Marine Corps and likes Barbados as well as any country he has seen.

"It's easier going here, more laxadaisy," he said. "In France they didn't like us."

A friend standing on the balcony, Marine Sgt. John Clary of Sacramento, also a helicopter mechanic, said he has been on four military cruises in the Mediterranean. He calls these "meds."

"My last two meds, they were having demonstrations in Greece and Spain about us," he said. "This is a lot better than I've seen in other places."

"Better than cotton sleeping bags," said Kelly.

He took another drag on his cigarette. Then, the complete soldier, he looked up and asked, "By the way, you don't know if there's a Catholic church around here anywhere, do you?"