Costa del Sol--an affordable spot in sunny Spain

RETIREES and others who have the time needed for long vacations can't always afford an extensive stay at an expensive resort hotel. One of the more frugal alternatives is a lengthy visit in sunny Spain. The Costa del Sol - the country's southernmost coast, facing North Africa across 20 miles of water - offers palm trees and flowering plants in winter, even though the climate isn't really tropical. You can sit comfortably in your bathing suit and get a suntan, but only the intrepid will actually venture into the water. Still, this moderate climate beats the fog and frost of winter in northern climes.

In recent years more Americans and Canadians have been joining the British, Scandinavians, Germans, and Dutch who have long been coming for stays of a month or longer in Spain, where the winter weather is springlike and where Americans still get good value for diminished dollars.

For example, a 10-week package, including air fare, room, and breakfast for 10 weeks at the Timor Sol costs $1,159 per person. A 28-day package, including air fare from Canada (Jan. 6 departure) at the Sunset Beach Club, costs (Canadian) $1,369 per person double occupancy, plus tax. And there are many other options available from the United States and Canada for longer or shorter stays.

Last year I traveled to the Costa del Sol on my own. Everywhere I went I found the Spaniards friendly and helpful and - with the exception of some big-city taxi drivers - honest. Just the same, I wouldn't go on my own again, but would choose a package trip instead.

If you go, don't expect to find picturesque fishing villages along the shore. The demand for sumptuous villas, houses, condominiums, rental apartments, and hotel rooms is so great that a strong building boom has been going on for years, transforming what used to be villages. The 43-mile-long beach strip, including the towns of Torremolinos, Benalm'adena, Fuengirola, Marbella, and San Pedro de Alc'antara, is made up of crowded cosmopolitan resorts, with clusters of 10- to 15-story apartment buildings.

East and west of the strip and in the hills inland one finds smaller resorts, bound together by an efficient and inexpensive bus line.

Like most resort spots, the Costa del Sol offers a lot to do and see: marinas with everything from yachts to pedal boats for rent; 14 golf courses; tennis clubs and public courts; swimming pools (some enclosed and heated); the palm-lined Paseos Maritimos for strolling along the beach. Added to these are the day trips one can make to the ``white towns'' in the hills; to Gibraltar to see the Rock and the friendly apes; to the 14th-century Arab Alhambra in Granada; and to the high peaks of the Sierra Nevada.

This is also a great place to begin or renew horseback riding. It's possible to join the Alondra riding parties on mountain trails and discover unspoiled Andalusia, with its famous horses and many riding schools.

Other activities such as shopping, dining, and entertainment can be found close by. Shopping is a favorite pastime among visitors here, with nationally produced items like Lladro figurines and cultured pearls widely available. For entertainment, the variety ranges from flamenco song, dance, and guitar to discos, charity galas, fashion boutiques, casinos, and the Ballet Contemporaneo de Madrid in Marbella.

Most first-time visitors come to Torremolinos, the one place everybody seems to have heard about. This city is sprinkled with touristy hamburger and hot-dog stands, fish 'n chips restaurants, electronic-game parlors, and souvenir shops. But if you stay on the Paseo Martimo, along the beach, you don't encounter much of this. Fuengirola is larger than Torremolinos, and its fast-food places are not so conspicuous.

Americans on package trips generally get complete briefings from a local English-speaking representative of their tour operator. But most important, the hotel rates and apartment rents in all categories are much lower for tour operators and their clients than for individual travelers. You also get lower tariffs on group flights, and you are taken right to your hotel.

American and Canadian tour operators advertise ``basic'' packages and ``upgraded'' hotels. I stayed at three hotels in the basic package - the Don Pablo and the Las Palomas in Torremolinos, and the Las Palmeras in Fuengirola - and found they had good locations, lots of space, and nice rooms and balconies. They also offered programs to keep you busy all day, including classes in the Spanish language, cooking, drawing, handicrafts, exercise, and archery.

Your booking can include half board or full board at your hotel, but since hotel food can be repetitious, I prefer to eat out. A nice meal costs between $4 and $7, without beverage. My favorites: the Florida (a smorgasbord, run by Danes) and the Pergola (Italian), both in Torremolinos; the Jasmin in Fuengirola; and the modest, open-air restaurants on Marbella's Paseo Maritimo.

If you go

Your travel agent can book prepaid trips through these tour operators:

In the US: Sun Holidays, Stamford, Conn.; Odysseus Adventures, Cedarhurst, N.Y.; Plus Ultra Tours, New York, N.Y.; and Petrabax, Rego, N.Y.

In Canada: Conquest, Thomson Vacations, and Fiesta, in Toronto, or Paramount Tours in Montreal.

Additional information can be obtained from Iberia Airlines of Spain, tel. 800-221-6742 in the US, or (416) 964-6625 in Canada. National Tourist Offices of Spain can be found in San Francisco, New York, Chicago, Houston, and Toronto.