"The Commerce of the West India Islands is part of the American System of Commerce. They can neither do without us nor we without them. The creator has placed us upon the Globe in such a situation that we have occasion for each other. We have the means of assisting each other, and politicians and artful contrivances cannot separate us."

The words of John Adams, president of the United States from 1797 to 1801, are as true today as they were when he spoke them. Whether the commerce results from the lemming-like rush of northerners from cold to warmer climates at the first sign of winter or from business ventures resulting from President Reagan's Caribbean Basin Intitiative, we still need each other.

As a host, the islands along the eastern rim of the Caribbean Sea have never been more welcoming. I think this is the best place in the world for warm-weather wallowing, with superb sailing, formidable fishing and enticing 18th-century legends. Several posh hotels finally are offering service and cuisine worthy of the spectacular natural surroundings, and new resorts are specializing in European-style elegance. At the same time, there are more (and better) small hotels for inexpensive and comfortable lodgings.

Restaurants and services have also improved: There are more good restaurants than ever before, and a kind of Caribbean cuisine is developing, with distinct variations from island to island.

Activities are highly organized on many islands and are excellent on some. Scuba and sailing facilities, always available, meet the highest professional standards on many islands, and a link between the Caribbean Hotel Association and the Caribbean Underwater Resort Operators assures increased bonding in the future.

Airline deregulation has resulted in lower airfares for some of the bigger, more visited, islands, as competition for the lucrative routes results in gimmicks to get new business. And you can get to almost any island by linking a low-cost main route with a small plane or boat connection.

As for the political picture, things have settled down since the U.S. invasion of Grenada in October 1983. Whether onlookers choose to call the action an invasion or a rescue mission, the fact is that the United States involvement at the request of the governments of the five small nations in the Organization of East Caribbean States, plus the bigger islands of Jamaica and Barbados, cleared the air. Many Caribbean governments became acutely aware of the possible impact of flirting with the Soviet bloc, and most have clearly stated their interest in free-market economy.

Most islands are also acutely aware of the need to shore up their flagging economies with more than fickle tourism, where today's "in" resort becomes next year's failure on the whim of a traveling public. President Reagan's Caribbean Basin Initiative (CBI), a three-pronged assistance program of trade, aid and tax relief, has spawned assorted joint ventures between U.S. firms and island businessmen, in businesses ranging from computer components to agriculture.

But there are problems this season, as well. There is petty crime in some areas, although visitors who exercise normal precautions need not be apprehensive. Ask your hotel manager and other residents about the advisability of "escaping" to some remote beach: It's perfectly safe in most cases, but may not always be wise.

The problems of heavily populated communities around the world are those, also, of Caribbean islands. Leave expensive jewelry, lavish wardrobes and bundles of cash at home. Take traveler's checks in small denominations, keep wads of bills out of sight, have small change when you travel around the countryside and be circumspect with expensive cameras and other equipment.

Tourism has brought its share of rip-off artists to all islands. Be aware that they exist, and be cautious when you buy to be sure you're getting what you want. Since all beaches are public, some are festooned with salesmen. The beach purveyors can be pesty. A firm but pleasant "No, thank you" as a salesperson approaches is usually enough to send them elsewhere. If you pause to look, you're fair game, and extricating yourself from the persuasive sales pitch may take some time. (Marijuana, cocaine and other drugs are also offered by some beach vendors; these drugs are illegal on all islands. You risk jail and/or fines, and an unsympathetic local government, if you're arrested.)

When considering the Caribbean, there are any number of choices. Here are some hints on what to expect this season:

*Anguilla, a sliver of beach-fringed land 20 minutes by ferry from the north shore of French St. Martin or a seven-minute flight from Sint Maarten's Juliana Airport on the Dutch side, claims one of the Caribbean's most luxurious resorts, Malliouhana, where an Amateur Tennis Tournament will be held Nov. 10-17 for the opening of new facilities. Cinnamon Reef is another first-class resort, the Mariners gets top marks as a comfortable seaside inn and Easy Corner Cottages offer apartment units.

*Antigua-Barbuda, a two-island nation known for beaches, sailing and the historic restoration at English Harbour -- the 18th-century haven for Admiral Nelson's fleet, offers elegance at Long Island Resort. The original 12 cottage rooms have been joined by 16 in a new pavilion on Jumby Bay, and a "private island" atmosphere prevails. The St. James Club is the new name for the completely refurbished former Halcyon Reef, where a European-style casino and well-kept riding horses are added diversions. Jolly Beach (on a superb beach) offers one of the best package plans. On Barbuda, Le Village Soleil offers casual beachside cottages on a gorgeous miles-long beach, shared only with luxury Coco Point, which continues to welcome corporate giants and others who seek (and pay for) "the best."

*Aruba's casinos keep its Palm Beach high-rise hotels lively, while the low-rise hotels settle on nearby shores. Look for good-value package plans that include air fare and hotel room.

*Barbados, an island with "everything," presents many of its small hotels in a booklet called "Barbados' Little Hotels," available free from the tourist board. The new Heywoods Resort has accommodations that include hotel rooms and self-catering lodgings, restaurants, pools, tennis courts, shops and water sports; Marriott's Sam Lord's Castle offers similar amenities. Best values come with package plans that include air fare and room. Hidden in the hills is one of the Caribbean's nudist camps.

*Bonaire, Dutch-affiliated and popular with scuba divers, has two comfortable hotels (Flamingo Beach and Hotel Bonaire), plus several small spots, each with its own personality.

*British Virgin Islands, northeast of the United States Virgin Islands, are special for sailors. Peter Island Yacht Club has new rooms on the beach this season. Tortola's Prospect Reef Resort includes a spa vacation among its offerings; Sugar Mill Estate Hotel, now owned by a chef/food writer couple, serves Tortola's best meals. Tradewinds and Biras Creek have an ownership/management link on Virgin Gorda, and both are near the charming, small nautical Bitter End Yacht Club. Little Dix Bay continues to offer top-notch comforts, with tennis, sailing and seclusion. Very casual camping is possible at Brewer's Bay on Tortola and at Tula's N & N Campground on Jost Van Dyke.

*Cayman Islands, south of Cuba and west of Jamaica, continue to add tastefully built condominiums and other rooms for rent. Seven Mile Beach, also known as West Bay Beach, is home base for most hotels and apartments, with Caribbean Club and West Indian Club the luxury leaders. Cayman Kai, across North Sound, is a total resort, with cottages, beaches, tennis and scuba. Spanish Cove has a scuba focus. On Cayman Brac, the new Brac Reef is less than a mile west of the former Brac Reef, now called Tiara Beach Resort and linked to the Aruba and Bonaire Divi-Divi scuba-focused hotels.

*Curacao, off the coast of Venezuela and one of the Dutch-affiliated ABC's (with Aruba and Bonaire), struggles with its bank secrecy provisions and their conflict with eligibility for U.S. convention groups and other aid. Popular as an off-shore banking area, the island's best property is the Venezuelan-linked casino-punctuated Concorde Hotel, the refurbished former Hilton. Small Avila is a personal favorite. Look for innovative package tours for bargain rates.

*Dominica, an agricultural island that appeals to botanists, is also appealing for investors. The country's dynamic Prime Minister Eugenia Charles, spokesperson for the OEC when the Grenada action was announced, continues to seek aid for her country's infrastructure and economy. All hotels are small, personality places that appeal to adventuresome travelers. Mountainside Springfield Plantation is one special spot; Sans Souci Manor's apartments are another.

*Dominican Republic, making headlines while its citizens grapple with severe economic problems, has some of the Caribbean's best facilities and values for this winter. The north-coast development at Puerto Plata has its own international airport, 18-hole golf course, long sandy beach and cluster of new hotels and apartments. Playa Dorada Holiday Inn is the only place on the beach; all others are a short walk from the shore. Jack Tar Village gives a good all-inclusive vacation week. Pool-flecked hotels in Santo Domingo, the capital four hours drive away on the south coast, are comfortable bases for business and visits to the 16th-century historic center.

*Grenada, at the southern end of the crescent of islands, will open its controversial international airport (started with Cuban and Eastern bloc assistance and finished with U.S., Canadian and European aid) on Oct. 25, the anniversary of the 1983 action. Lodgings are in small and special inns, with the absence of the Grenada Beach (now the barracks for visiting troops) and Ross Point (now the United States Embassy). Look for interesting vacation packages as soon as the new airport is in full operation. The capital is charming; beaches are good; the countryside is mountainous, lush and tropical.

*Guadeloupe grapples with local factions who seek independence from mainland France. Francophiles can find some good values this season by playing the French franc market; look into the air-plus-room rates offered by the "Fete Francaise" holidays and plan to spend French francs for island-incurred expenses. This can be one of the Caribbean's best bargains, and is the source for some of the region's best restaurants. Speaking French helps -- a lot.

*Haiti, still struggling with severe economic problems, has some of the Caribbean's most charming hotels, many with very reasonable rates this season. Look into Castel Haiti and Le Plaza Holiday Inn for expected U.S. comforts and package plans. Hotel Splendid, Grand Hotel Oloffson and Petionville's Villa Creole get high marks for atmosphere and hospitality. Count on service everywere to be willing -- but slow. Beach places are casual, led by Kaliko and action-packed Club Med. The country is a popular partner for U.S. joint ventures.

*Jamaica is making progress in its campaign for a viable economy, and tourism is accepted as a national occupation. Port Antonio's pace-setting Trident Villas has acquired the former Jamaica Hill, renaming it Trident Villas at San San (the residential area where it is located) and offering butler and maid with each unit. Tryall, west of Montego Bay, runs its Great House and bevy of rental private homes as an elegant resort, and Round Hill greets this season with its special luxury flair. The former Hilton near Ocho Rios is now Eden II; Sandals, near Montego Bay's airport, continues to set precedents for its all-inclusive week-long plan, a trend started by popular Couples Resort, east of Ocho Rios; Hedonism II at Negril is another all-inclusive spot. The "Innside" plan for Jamaica's small hotels is worth investigating. Ask the tourist board for details about it and camping facilities. This is a good place to investigate joint business ventures.

*Martinique shares the French nationality and the franc exchange with Guadeloupe and sister islands. Francophiles should calculate the costs of package plans promoted in dollars to be sure that the value is better than buying minimal air-and-room and paying in francs on the spot. Club Mediterranee continues to offer comprehensive week-long plans. Several small spots can give you Mediterranean-style France; self-catering places are comfortable, but not luxurious. Restaurants abound, and are best when they're small and bistro-like, as they are along the beach at Anse Mitan, across the harbor from Fort de France.

*Montserrat, a British-affiliated territory that's about a 15-minute flight from Antigua, is an away-from-it-all island with plenty of homes for rent. Be sure to check location: Places that seem inexpensive may require a rental car for mobility. Folksy Vue Pointe continues to be the island's only resort-style hotel. There are also a couple of small and very simple spots. High-quality handcrafts and joint ventures are interesting here.

*Nevis, the southern sister of the nation of St. Kitts-Nevis, holds some of the Caribbean's most enchanting small hotels, most of them incorporating former plantation houses and surroundings. Hermitage Plantation's simple apartments are news for this season. Rates are high at resorts on this quiet island because demand is.

*Puerto Rico faces this season with a revitalized tourism and political ferment that will be resolved with the November elections, when the governor runs for re-election amid debates about Commonwealth status versus independence or statehood. El San Juan Resort, not far from the airport, has reopened under management related to Condado's successful Holiday Inn resort. The Caribe Hilton continues to be my top choice among San Juan hotels. Count on good prices for multi-day stays at the big hotels, and look into the guest houses in the San Juan/Condado area as well as those around the country. The Paradores Puertorriquen os are the leaders; Centro Vacacionales are camplike communities, and the former U.S. military base at the west end has been revamped as a vacation center. Offshore islands of Vieques and Culebra are coming into their own, as places for small business ventures as well as for small hotels. The Parador Esperanza on Vieques is a nice newcomer, with self-catering apartments and a beach.

*Saba, a "pyramid" in the sea south of Sint Maarten, has a few guest houses. The Captain's Quarters in Windwardside, popular for lunch by day-trippers from Sint Maarten and for overnight by escapists, has scuba facilities and a pool; Cranston's Antique Inn in the Bottom beds guests in four-posters. Prices are set by the island's popularity as a hideaway.

*St. Barthe'lemy, French in its affiliation and currency, continues to be "the" place to be seen, especially in winter months. Island government regulations limit hotels to 12 rooms, keeping character intact. Emeraude Plage, a special spot on a lovely beach, has added cottages for this season, and Manapany Cottages are independent units on the hillside above Anse des Cayes. The French franc should benefit here, but the island deals mostly with Americans in winter -- and prices accordingly.

*St. Croix, the largest of the U.S. Virgin Islands, has gone all-out for hospitality. Special customs allotments for U.S. travelers make shopping for imports attractive. Refurbishing at Buccaneer Hotel and Beach Club secures its niche as the island's top spot; bushels of money lavished on Grapetree Bay and its sister Grapetree Beach Hotel put those places in good shape; and elaborate plans for the Fountain Valley golf course and beach area by its new owners mark that northcoast resort for luxury status.

*Statia, formally known as Sint Eustatius, has few changes from season to season. There continue to be only a handful of small spots for folks who want peace, quiet and time for contemplation. Mooshay Bay and Old Gin House are the leaders, with rental bicycles one of the action options.

*St. John, best known as the site of the 29th U.S. National Park, is a 20-minute boat ride from its more commercial U.S. Virgin sister, St. Thomas. Caneel Bay Plantation continues to be the uncontested luxury leader, but the apartments at Gallows Point, overlooking Cruz Bay, are worth looking at if you want self-catering. Maho Bay Camp, with canvas "curtains" on wood frames for basic shelter, has its devotees, as do the 40 cottages plus 40 tent sites at the Cinnamon Bay Campground. Private homes and apartments are available through local realtors.

*St. Kitts, the seat of government for the British-affiliated nation of St. Kitts-Nevis, has several attractive inns as well as a growing resort at Frigate Bay. An enthusiastic supporter of the CBI, the Kittitian government encourages joint ventures and outside investment. The Royal St. Kitts, with its casino, tennis courts and golf course, is the island's biggest resort. I think the best are the small-and-special Rawlins Plantation and the Golden Lemon, with Basseterre-based Ocean Terrace Inn ideal for island aficionados and businessfolk.

*St. Lucia, one of the Caribbean's most beautiful islands, continues to straddle old ways and new challenges. Couples II, affiliated with Jamaica's successful all-inclusive resort, gives good value, as do special plans at the St. Lucian Hotel. Marigot Resort, south of Castries, offers cottages, apartments and hotel rooms with a sailing emphasis at Marigot Bay, while the northern sector's Rodney Bay and Castries also have marinas and boats for charter. Dasheen and Anse Chastanet are personal preferences for hideaway havens on the quiet southwest coast. The climate is comfortable for business ventures and investment.

*St. Martin/Sint Maarten, Janus-like with Dutch and French "faces," has the Caribbean's most elegant shops. La Samanna continues to be one of the Caribbean's top 10 resorts, and quiet Oyster Pond's new look makes it a special small spot. Cupecoy, Grand Case and Le Grand St. Martin are three places offering exceptional apartments with beachside location. Club Orient is the nudist resort that flourishes on the French side's Baie Orientale. Restaurants are exceptional, and expensive, with Poisson d'Or and Le Santal two French-side favorites, and Il Pescatore and the Indonesian food at Wajang Doll two of my Dutch-side favorites.

*St. Thomas, capital of the U.S. Virgin Islands, stretches out from its busy capital of Charlotte Amalie to the offshore islands, where you can find some restaurants and resorts, and to the north shore, where pace-setting Mahogany Run has what some say is the island's best restaurant, the Stone Farmhouse. Bluebeard's Castle, on a hill in town, is the island's most convenient resort (with transportation arranged to a beach); Frenchman's Reef is the biggest. Condominiums rent at reasonable rates, especially for groups. Some small inns have reasonable rates. Boat links to nearby islands, plus the special U.S. customs allotments for the U.S. Virgins, make this destination a favorite for those who want shopping with sun, sand and sea.

*St. Vincent and its Grenadine Islands, west of Barbados and south of St. Lucia, elected a new, young government in July. Bequia-born Prime Minister James Mitchell governs the multi-island country, which holds some of the Caribbean's most enchanting terrain. Small hotels are often simple, comfortable and uniquely West Indian. Luxury comes with a price at Young Island and Petit St. Vincent. Palm Island Beach Club also occupies its island, and Cotton House, on Mustique, coddles the world-weary.

*Trinidad, cosmopolitan country with its sister Tobago, struggles with an economy that spurted to enviable levels with oil in '77 but lagged when prices fell. Intriguing for worldly travelers, including those with business interests, the island has one of the Caribbean's most comprehensive nature centers at the Asa Wright Reserve, as well as a pace-setting Carnival. Hilton's lodgings top the list.

*Tobago, the relaxing "half" of the country of Trinidad & Tobago, shares peripherally in the oil influence, but thrives on being the vacation island, not only for outsiders but also for Trinidadians. Mount Irvine Bay Hotel is the luxury leader, with private homes for rent on the premises the best of the lot. Several shoreside hotels have good facilities, and most are included in the "Just the Two of Us" vacation plans, as well as some scuba sessions.