British newlyweds Ernest and Angela Chiu thought their visit to the tiny Caribbean island of Grenada this month would be a honeymoon in paradise. Instead it turned into a nightmare of war that almost cost them their lives.

Both recent graduates in economics from an English university, the young couple picked Grenada for their honeymoon after they were married Oct. 1 because it sounded tranquil and ideal.

"We looked through all the brochures about the Caribbean islands looking for a quiet place with a calm beach where not too much was going on," recalled Angela, 28, after her evacuation to this neighboring island late last night. "We thought Grenada was it."

That was until they were awakened in the bungalow of the Spice Island Hotel on Grenada's Grand Anse Bay at 4 a.m. Tuesday by the incessant noise of low-flying jets and helicopters overhead. Though they weren't to know it until hours later, that was the beginning of the invasion of the island by a joint task force made up of U.S. marines and paratroops with soldiers and policemen from six neighboring Caribbean islands.

For the next 36 hours, Angela Chiu recalled, she and her husband lived in terror, spending much of their time crouched in the bathtub of their bungalow while fighting raged in and around their hotel, next to one of the two campuses of the St. George's University School of Medicine. It was the safety of the school's more than 600 U.S. students that was one of the justifications for U.S. intervention against the Marxist military government of Grenada.

"I was scared all the time," Mrs. Chiu said. "I thought we were going to be killed. I never heard a more frightening noise. It was as if thousands of troops were firing all around us."

Planes swooped overhead steadily, many discharging rockets and gunfire at targets that the Chius could not see. There were explosions in the capital of St. George's, across the bay from their hotel. In one instance, the Chius both said, they actually saw bombs drop from two jets swooping over the city.

"At least I thought they were bombs," Mrs. Chiu said. "They were long, silvery cylinders with pointed noses."

After the first 24 hours of fighting, there was a lull yesterday morning that allowed them to emerge from their bungalow at breakfast time and survey their surroundings with binoculars.

"We could see Fort Rupert a garrison of the Grenadan Army above the capital and it was full of big holes," Mrs. Chiu said. "The office of the former prime minister, Maurice Bishop, had also been gutted by fire. There was no roof left, just the walls were standing."

It was the assassination of Bishop, three of his Cabinet ministers and two prominent labor leaders by the Grenadan Army Oct. 19 that led to the decision by the United States and the six members of the Organization of Eastern Caribbean States to intervene against the Cuban-backed Revolutionary Military Council that replaced Bishop as ruler of Grenada last week.

The worst moment of all for the Chius and an American couple, Mr. and Mrs. Jack Mozela, who cowered with them through their ordeal, came yesterday afternoon when the slow-moving U.S. invasion force finally reached the medical school.

"Suddenly we heard loads and loads of gunfire all around us and helicopters overhead," said Ernest Chiu, who was born in Hong Kong and moved to England. "It sounded as if everyone was firing at our bungalow.

"Someone shouted to us from the beach to get down and we jumped back in the bathtub. Then, after another five or 10 minutes of intensive shooting, there was another lull and someone yelled, 'This is the U.S. Army peace-keeping force. Run and run fast.'

"We ran to the beach and I remember looking up and seeing the soldier with his face all covered with black paint and covered in sand. I was so scared my mouth felt as if it had turned to concrete."

Once on the beach, the couple and the Mozelas were rushed down about 100 yards to where five or six giant Sea King helicopters were standing, their rotors whirling and their bay doors open to receive evacuees. The choppers took off for Point Salines, the headquarters of the invasion task force.

From there, the evacuees were boarded on a four-engine C130 Hercules transport and flown to Barbados, where only the Chius, as British citizens, were allowed to disembark. All the other Americans in the plane were forbidden to get off in Barbados by the U.S. military authorities and forced to fly on to the United States, even though some of them, like the Mozelas, apparently had hotel reservations waiting for them in Barbados and had asked to be allowed to stay there.

"I remember Jack was so upset by the whole thing that he said if he had known what was going to happen, he would have chosen to stay in Grenada," Mrs. Chiu said. "After all, 'til the invasion came, things were calm and we did not feel particularly threatened. We were quite happy at our beach bungalow until Tuesday."