CHOOSE A vacation island? If you've never been to the Caribbean and have an atlas, it looks an almost impossible choice - each name sounds more exotic than the last. Recently I had a week to spend somewhere warm, somewhere in what I termed the "$200-250 airfare Caribbean."

A couple of calls to air lines ruled out Aruba, Antigua and Guadeloupe on grounds of air face (a package tour would have met my price limit, but my time span wasn't right). All flights to Jamaica at that time were booked, but Jamaica seemed too British (which I am). And my traveling companion eliminated Nassau and Puerto Rico as too American (which she is). We wanted something different. As we talked, Haiti seemed to have it all - warm, exotic and French-speaking (both of us speak a reasonable fac-simile of French).

With no more forethought than that, we set off, looking forward to a restful week on a beach in the sun. We flew nonstop from New York (round trip $255 including a connection from Washington), but I returned via Miami, which is equally convenient and the airport is less subject to bad weather. In three short hours we were disembarking at Duvalier Airport, Port-au-Prince, blinking in the afternoon sun.

Haiti became relatively inaccessible to Americans during the '60s under the regime of President Francois "Papa Doc" Duvalier, when his strong men ("Tonton Macoutes") terrorized the countryside. What tourists there were mostly Canadians - we were always being asked if we were Canadian. But Papa's son, known affectionately or wryly as "Baby Doc" and officially as "President for Life Jean Claude Duvalier," says he wants to improve his country's appalling economic conditions, and part of his plan is to encourage American tourists and American industry to put Haiti on their itinerary.

As it turns out, it is not easy to be a tourist in Haiti - although there is plenty of opportunity for affluent isolation in resort hotels - but it is tremendous fun. Port-au-Prince is a sprawling, dirty, teeming city and its greatest problem for foreigners confronts them right away - transportation. Once we had figured out the esoteric methods available of getting from A to B without paying $25, the city was at our feet.

Strange little buses called "tap-taps," constructed on flatbed trucks and decorated over every inch with paintings of flowers, animals, Bible stories and proverbs, ply along the Avenue des Salines parallel with the harbor at intervals of seconds. They stop when you wave and have an impenetrable fare structure. Drivers will demand anything that comes into their heads from tourists - known frankly among Haitians as "les blanches." The local fare is 10 cents to go anywhere. A tattered one gourde note (a gourde is worth 20 cents) will pay for two.

We found that handing the driver the note with a firm "merci" and walking briskly away took care of most of the arguing. Every driver we asked to let us off at a specific destination remembered to let us know, in fact everyone on the tap-tap made sure we got off when we should.

Tap-taps run only horizontally. To go vertically up the hillside or down to the bay one takes a "chiffon rouge." We had read about these, but it takes a while to spot them. They are ordinary sedans with a red scarf tied to the front driving mirror. Station wagons marked "Petionville" go up the hillside to the resort hotels. We paid two gourdes to go the seven miles, although regulars told us one would have been enough if we were willing to fight - but we were on vacation. (We had studied Fielding's 77 "Guide to the Caribbean" with minute care before we set off, but it failed to explain how tap-taps worked.)

All this talk of how to get around - such a basic for travelers - of course brings up the question of language. Fielding's informed us that 90 per cent of Haitians spoke Creole and only 10 per cent French. In seven days in Haiti, I encountered only one young boy (up in the north) who had difficulty with French, and the clear unaccented French of almost everyone was a joy to hear and easy to understand.

Negotiating, arguing and getting around was, of course, made easier by the fact that we both spoke French, but language is really no problem for those who stick to the large hotels and the tourist trail. But speaking French brought the country alive. Admittedly, it did have some disadvantages. It laid one open to all the complex ill-luck stories that accompanied every demand for money. In his efforts to extract another 50 cents, my guide at the Citadelle even launched into a variation on the orphan theme that had his father falling off the top of the fortress and his mother dying of griefK. The cheerful beam that accompanied this gruesome tale made me skeptical, but I couldn't help feeling that his imagination had earned him his money.

Budget considerations made us avoid the lovely and luxurious resort hotels of Port-au-Prince, so we stayed in a guest house with the inviting name of "Le Sourire Magique." It turned out to be in the cheerfully slummy district of Fontamara, and somehow we managed to get there by tap-tap from the airport, avoiding a fleet of rapacious taxis. Our double room (with a bathroom and a distinctly unpredictable supply of hot water) and a substantial breakfast cost us $12.50 a day each. Not luxurious but clean, with a small swimming pool, and well run by "Madame Yvette," the mysterious figure in the background who rationed the toilet paper and threw the parties.

Life at the Sourire Magique, as we soon found out, was never dull. We had arrived in Haiti at Carnivale time, and Port-au-Prince is a swinging city at Carnivale. For the first 24 hours we thought the Sourire Magique was a quiet suburban guest house. Then we found that up on the flat roof was the local cockfighting ring and the social center for the whole of Fontamara. The ceiling creaked and vibrated as the throbbing of steel bands and dancing feet lasted far into the night. Every night, strange figures clad in gloulish masks would appear around corners and the house was alive with singing. Hardly the quiet vacation, but the gaiety was infectious. My companion, always a resourceful traveler, used manicure scissors and brown paper bags to fashion us a couple of sinister headpieces and we joined the party.

To turn briefly to the subject of beach - or rather of no beaches. Fielding's had warned us, but we were unbelievers. After all, it was the Caribbean with its bright, light-blue water. But this time they were right. Haiti is no place for a beach holiday. As soon as we had reached the Sourire Magique and sloughed off our winter clothes, we asked for "la plage," the beach? Answers were vague. "We'll find you a driver. Tomorrow. Maybe." As adversity is the mother of invention and we could see the water from our room, we persevered. "Oh, yes," there was a beach, "not very pretty," Madame warned. "Near, but 'artificielle,'" she added.

We set off in another tap-tap and journeyed for what seemed a very long way, fascinated with the coconut palm, the flowers, the street life, the graceful women carrying huge baskets on their heads. The feeling of a proud yet primitive country came through clearly even on our first expedition, as did an awareness of the tremendous poverty of Haiti.

Our driver decided he'd had enough for one day, traded us to another tap-tap and finally we reached "Le Lambi Beach Hotel." We walked in under the high straw roof crowded with tables - completely empty - and inquired about the beach. Most politely, we were directed to the front of the enclosure. There it was in all its glory. An elaborately constructed tray about 6-by-15 feet covered with two inches of loose sand, the whole suspended on stilts about 15 feet above the water! We both remembered "artificielle" and began to laugh and laugh. It was the kind of vacation when everything, even the disillusionments, was a pleasure.

We later discovered that Le Lambi was the headquarters for commercial voodoo displays in Port-au-Prince and that in the deep of the night for $4 a head, tourists could watch a squirmy approximation of voodoo dances. No wonder it was deserted at 4 o'clock in the afternoon.

There are several real beaches: Ibo, Kyona and Kaloa to the north of Port-au-Prince, all about 45 minutes to an hour's drive and relatively inaccessible for casual trips.

The folk arts and crafts of Haiti are truly magnificent. Primitive paintings are everywhere - some of them ghastly, many of them colorful, idiosyncratic and alive with talent. The idea of haggling over a painting is daunting for those like us with strong interest but little expertise, and we were very happy that we followed advice and bought our paintings from Issa El Saieh of Issa's Gallery, 17 Avenue de Chili, near the Hotel Oloffson. Issa was there in person in his gallery stacked with paintings priced from $20 to many thousands. No bargaining here. Pleasant advice, no pressure and a nicely framed reminder of the soul of Haiti - delivered to your hotel, and even to our obscure guest house. Issa also sells mahogany plates of all sizes; at prices ranging from 50 cents to $4 they were some of the best made we saw.

It was hard to tear ourselves away from Port-au-Prince, but to go to Haiti and miss the eighth wonder of the world seemed out of the question. King Henry Christophe's fortress in the clouds, his Citadelle on an impossible mountaintop, ready to repel the French invaders who never came (the cannon balls and still stacked waiting to be fired), is an unforgettable sight. Reaching it is an unforgettable Haitian experience involving a hair-raising flight across rocky mountains in a small plane ($37 round trip) and a two-hour trek on a half-starved horse (rented at the police station) up a rocky track.

We acquired an entourage of self-designated guides, horse boys and interpreters, repelled hordes of entrepreneurs and eventually did make it to the top, where the fortress sits massive above the clouds and the Coke is $2 a bottle. Only I saw the rusting cannons, the crumbling keep and soaring battlements, for my friend suffered a violent attack of vertigo and was forced to sit against the wall with her eyes closed while I saw the sights. Fortunately this was Haiti, and for 50 cents we hired two stalwart youths to carry her down bodily to where her horse was recovering itself on more level ground. You can go up most of the way in a Land Rover for some extortionate price, but we would not have missed that creaking, scrambling, bonebreaking ride for the world.

We went up to the Citadelle and back to Port-au-Prince in one day and it was an exhausting one. It would be more pleasant to spend a night in nearby Cape Haitian.The next day, aching all over, we felt like a leisurely swim and a quiet lunch. Although we did not stay in one of the famous resort hotels, we lunched in several of the most recommended. Almost everywhere the staff was unfailingly pleasant and accommodating when we asked if we might swim before taking lunch, even though we were not registered guests.

The Plaza, right in downtown where double rooms run around $40 a day, had a pleasant poolside restaurant, and the Villa Creole up in Petionville ($50-$60 double) was inviting enough for two visits - the pool looks out across the mountains and for $4.50 each we ate an appetizing three-course lunch. Only the somehow decadently sumptuous Habitation LeClerc proved disdainful and unwelcoming to drop-in visitors. After glancing at the layouts from Playboy, Penthouse and Oui featured prominently in the lobby, and learning that the tab was $125 a day per couple, we found we didn't care to stay anyhow - although the architecture and planting is certainly worth a look.

We also had lunch by the pool of the brand new Royal Club Haitian and returned one evening with $10 apiece to see how long we would stay in business in the plush casino. It was filled with big spenders on trips from Miami. We lasted about four minutes at the roulette table.

Not too much sleep and no lying on the beach at all, but a vacation second to none, and an island we shall not forget.