Sailing with my wife and me were older brother Jim and older sister Priscilla. I had told them about cruising life in the Antilles and its special delights, among them the endless beach of Barbuda. This wasn't like taking the kids the first time to Disney World: My siblings have been around. s Jim was in the navy during World War II and knew all about beaches because he served aboard an LST, which was designed to come up on a beach to disgorge troops, tanks, and spare parts. s Priscilla had wandered with me for several days in the Tahitian islands, including the fabulous Bora-Bora, and, once before, we had sashayed around what I insist are the most beautiful islands in the world - the Azores. But the Azorean beaches suffer from dusky gray sand, in contrast to the white-white beaches of the Antilles. (I remember speculating on whether the old trick of the adman in the Thirties might work to sell the Azores to the tourist world. He was hired - remember? - by a fishery trying to unload an aberrant million pounds of snow white salmon. He came up with the slogan, "Guaranteed Not to Turn Pink in the Can!")

Our approach to barbuda was restricted, when the skipper of our chartered Swan 65 advised me, with heroic equanimity, that the noise I had heard during the preceding half hour, as we bounded under sail from Antigua toward Barbuda in a happy easterly, had meant that the engine mount had "collapsed."

"How long would it take to repair?" I asked.

"Well, certainly not less than one week." But his young face brightened: "With the course you've set, we can sail all the way, and the generator's working just fine."

Who needed an engine?

But this meant that our tack toward the anchorage area, about a hundred yards from Barbuda's spectacular beach, had to end before the outermost reefs began, which left us a half mile from land. Yet we needed to press on, not only because of the special allure of the famous three-mile-long beach but also because we had our social obligations. My wife's old friends Arthur and Francisco were staying at the K-Club and had asked us to dine with them during our cruise.

And at the south end of the beach was Coco Point Lodge, founded and run by Bill Kelly, a college friend whom brother Jim had promised to visit.

"How old is the Coco Point Lodge?" I asked Jim as the sails came down. He didn't remember exactly but said that if I could remember when Princess Margaret Rose was married, that was when the lodge opened, because she had honeymooned there. Well, I didn't remember exactly when Margaret Rose and Antony Armstrong-Jones had married, only that it was many anni horribili back for the royal family.

But we were anchored off the K-Club, where Arthur and Francisco awaited us. The captain said he would take the dinghy in to the beach and advise me what was involved in stepping ashore.

A half hour later he was back.

"There's something of a¿swell," he cautioned. "But we can handle it."

Since my wife, Pat, has frail hips, thrice operated on, Jim and I decided to do a dry run in order exactly to evaluate the difficulty in landing on the island with our dinghy.

We approached, and the swell seemed quietly and nicely to subside. We were only feet away when a rogue wavelet crashed in, and we tumbled out in crotch-level water. Pat, it was now clear, would not be visiting this island, but I would attempt to discharge minimal social obligations, and Jim would visit a half hour with Bill Kelly.

With my cellular phone I told Francisco at the K-Club that we had arrived and were standing in the loamy sand within eye distance of his hotel.

Minutes later Francisco was, as always, breathlessly describing the amusements and vexations of life in general and life in particular. As we trudged up toward the clubhouse, he gave us two data relevant to our plans.

Concerning the destination of brother Jim, we should know something about the "problem" of the north part of the beach, the K-Club, and the south, Coco Point Lodge. Both are luxury resorts, he said, but the relations between the two owners were straight-out Hatfield-McCoy.

"It's like North Korea and South Korea," Francisco explained. The resorts do not have contact with one another, "so we'll have to make special arrangements," he said to Jim, "to get you from here to Coco."

And then, he chatted on, as we approached the lightly screened, aquamarine-and-white clubhouse (all but demolished three months earlier by Hurricane Luis but miraculously rebuilt in time for the season), there was the problem of Princess Diana.

We had been at sea a few days and were ignorant of what the society pages of every tabloid in the world were evidently whispering, namely that Di was on the island of Barbuda, staying at the K-Club.

"Alone?" I found myself asking, without malice aforethought, just spastic journalistic curiosity.

"She has her lady-in-waiting," Francisco explained. "They spend the entire time at the swimming pool."

I found this odd, given the lascivious wonders of the beach and also the two floodlit tennis courts, the nine-hole golf course, the snorkeling, the sailing. On the other hand there isn't actually that much to do on a beach, is there?

Arthur, who is a famous architect, had joined us - we were now sitting in the lounge across from the bar, Jim having made off across the DMZ to Coco Point Lodge - and nodded in vigorous agreement, because when he goes to the beach, he said, he goes in order to get a lot of reading done, whereas Francisco is a beach-nut who stretches out hour after hour, sun-worshiping. Beaches, Arthur and I agreed, are splendid to look at, not to plop down on.

They were enjoying the K-Club and its 250 acres on an island with 1,500 inhabitants. Barbuda, I was told, had a gruesome distinction: It was an island on which for more than 100 years slaves were bred. Thirty-five years ago, when the Coco Point Lodge was established, the island was completely undeveloped. Today 60 percent of its income is from tourists, and now it had the crown jewel, Princess Diana.

Her arrival had caused great commotion. Poor dear, she slipped out of Heathrow a day or two after Christmas, with her lady-in-waiting, onto a commercial flight to Antigua, using an assumed name. But, of course, one of the dogs of the press spotted her, and by the time her private plane (Antigua-Barbuda flight time, 15 minutes) had landed, a great legion of paparazzi had gathered, intending to make her stay on the island as exposed as possible.

To thwart this, the authorities in Barbuda had rallied. Among other things, they closed off a half mile of the great beach. This was not accepted without complaint. Francisco cited the owner of a local grocery store who was quoted in the papers as saying that "legally, we can access the beach and sit right next to her. I totally object to anybody shutting off what is public property."

Nor had Diana made time for the locals. On being asked to appear at a ceremony to present medals to people who had played key roles in restoring the island (95 percent of roofs had been damaged by the hurricane), she simply declined the request - not what was expected of someone who only weeks before had told the world she hoped to be thought of as the Queen of Hearts.

On the other hand, the Princess obviously sought isolation, given that she had chosen to stay in a club that excludes children under the age of 12, which meant that William and Harry wouldn't have been admitted, even if they could have been wrenched away from the prince, the queen, and the imperial guard at Sandringham, where they spent New Year's.

I was called to the telephone. it was my brother, speaking to me from across the DMZ. He reported that Bill Kelly suggested that I contact the captain aboard our vessel and warn him not to approach our designated rendezvous point, where we had landed 45 minutes before, because, night having fallen, he might hit one of the barely submerged reefs.

But there was no way to reach the captain. I didn't have a radio with me, and the captain was not monitoring any channel. Very well then, Jim would meet me in 15 minutes, as previously arranged.

As I returned to my hosts and my rum collins, a crew-cut, middle-aged man in casual dress addressed me.

"I'm Ken Follett," he said, "and Ed McBain is also staying here. Now that is a coincidence, isn't it - you, me, McBain? "

I told Mr. Follett I thought The Fist of God was one of the best suspense/espionage novels I ever read, and he said, thanks, but he didn't write it.

I plunged into another title, but he hadn't written that either. I told him I still winced at the review he had given one of my thrillers in the Listener, but he said he hadn't written it.

The only thing I could do under the circumstances was to congratulate Mr. Follett on whatever it was he had written (The Eye of the Needle; the other author is Frederick Forsyth). We wished each other a happy New Year.

The time had come, and Francisco and Arthur came with me to the beach, where we could make out the dinghy. We waited for Jim. He was almost ten minutes late. He had been stopped, after getting out of the Coco car and walking out to the beach, by the secret service guarding Princess Di's privacy. Jim was once a senator and is now a senior judge. He positively emanates sobriety. Not even Ken Follett would cast him as a terrorist.

Then it was back over the reefs to report to wife and sister all the news of the captivating island of Barbuda.