Rafting in Costa Rica. Costa Rica is often overlooked as a vacation spot because of unrest in other Central American nations. Yet, this peaceful, safe country boasts an ideal climate, beautiful scenery, and a wide variety of activities. Among them is white-water rafting, an exhilerating sport for novice and expert. Costa Rica Expeditions, which began rafting trips in 1979, sponsors one-day runs for $65 or multi-day trips ranging from $72 to $86, including equipment and meals. In addition, they offer natural history tours that explore jungles and volcanoes, and fishing expeditions on lagoons and backwaters. For a free brochure, write Costa Rica Expeditions, PO Box 6941, San Jos'e, Costa Rica, tel. (from the United States) 011 (506) 22-03-33. Inside the US, call International Expeditions in Birmingham, Ala., at 800-633-4734, or Sobek Expeditions in Los Angeles, at 800-344-3284. Singles don't pay more. Trafalgar Tours offers a single traveler the opportunity to purchase twin share offers without paying an additional supplement if a roommate isn't found. Also, for a full-fare tour, singles are guaranteed a set price, even if the currency of a particular country fluctuates. Trafalgar offers a wide range of programs for Britain and the Continent, including ones for under-35 travelers and older travelers and a series of deluxe tours. For more information write to Trafalgar Tours, 21 E. 26th St., New York, NY 10010, or call 800-854-0103 or (212) 689-8977.
Bird watching in Africa. A unique tour to the African island nation of Madagascar is being planned by Bird Bonanzas for Nov. 20-Dec. 7. Bird-watching enthusiasts will visit the island home of hundreds of birds, with 130 unique species evolved from species dating back millions of years. Participants will explore deciduous forests as well as rain forests and will stay in comfortable though rustic accommodations near the birding locations. For details write to Bird Bonanzas, PO Box 611563, North Miami, FL 33161, or call (305) 895-0607.
Austrian celebration in Belgium. Belgium's Europalia, a biennial festival dedicated to the culture of one particular European country, focuses on Austria this year. The festival, scheduled for Sept. 16-Dec. 16, will include more than 200 events, with displays of Austrian and Belgian art in various museums. Special performances and films are being planned in a number of theaters, and literary readings will be given. Austrian music will be presented by Belgium's major orchestras, as well as the famous Viennese and Salzburg orchestras. For a brochure outlining the events of Europalia, write to the Belgian National Tourist Office, 745 Fifth Ave., New York, NY 10151, or call (212) 758-8130.
Watercolor Workshop in Hawaii. The Hyatt Regency Waikiki is presenting a series of watercolor workshops to be conducted by renowned watercolorist Dong Kingman. Kingman's works have been displayed in many museums around the world, and he is the recipient of numerous awards and honors. The workshops are scheduled for Nov. 22-29, as part of a package including seven nights at the Hyatt Regency Waikiki, and five watercolor classes. The cost of the entire package is $1,195 per person double occupancy or $1,550 single occupancy. For more information write PO Box 82266, San Diego, CA 92138, or call Thurman Hewitt, director, Hewitt Painting Workshops (619) 222-4405.
The Amazon with Irving Stone. You can sail to the Amazon aboard Cunard's Sagafjord with author Irving Stone, who will be on board to speak with passengers about the journey and his own writings on South America. The cruise departs Fort Lauderdale Oct. 16 and will stop at eight ports in the Caribbean, including the infamous Devil's Island. Once on the Amazon, passengers will visit Santarem, Alter do Chao Beach, and Manaus, capital of Brazil's rubber industry. There will be scheduled side trips, including a river voyage into Peru. For more information contact Delta Tours, San Francisco, or call 800-752-SAIL. In California call (415) 542-SHIP. Spaces are limited.
Irish countryside. It's not too late to spend eight days exploring the Irish countryside and cities this summer with CIE, Ireland's national tour company. CIE's seven-night offer includes round-trip air fare from New York to Dublin, first-class hotel accommodations, and full Irish breakfasts daily, as well as five dinners and luxury motorcoach service with tour directors. The price of the package is $1,047. The CIE tour includes visits to Dublin, Killarney, the Ring of Kerry, Waterford, Wicklow, and more. For details contact a travel agent, or phone 800 CIE-TOUR (800-522-5258 in New York and 800-331-3824 on the West Coast).
Barge travel in the Netherlands. A late-summer or early-autumn cruise through the canals of Holland and Belgium aboard the Rembrandt hotel barge gives the traveler a unique view of these two scenic countries. Departures are scheduled for Sept. 10 and 24. Passengers will take an excursion to Het Loo, visit the Van Gogh museum, explore the harbors of Rotterdam, and walk the winding streets of Ghent and Bruges. The price of the six-day cruise is $1,795 per person, double occupancy, including hotel and barge accommodations, meals, sightseeing excursions, and an escort. For a brochure, phone William D. Buckman's Travel Time at 800-621-4725 (or from Illinois at  726-7197).
Traveling with tots. From a brochure on ``Kids Fly Free'' come the following tips for parents traveling with children:
Make air reservations early to take advantage of a larger selection of seats and possibly lower fares.
Make a list of reminders before leaving home so that no travel need is overlooked.
Carry a separate bag for travel essentials: diapers, bottles, games, books, snacks.
Take advantage of pre-boarding announcements for families with small children so that everyone can get settled as quickly as possible.
For safety's sake and consideration for others, try to keep children calm and seated, with their seat belts fastened during flight.
For the brochure on family travel and information about the ``Kids Fly Free'' promotion, co-sponsored by Chex cereals and Piedmont Airlines, call 800-251-5720.