Q&A
LEAD: San Diego Trips  Question:I would like to take a cruise of three days or so from San Diego down the coast of Baja California, Mexico. If there is such a cruise, on a small ship, who administers it? - Z. C. M., New York, N.Y.  Answer:Opportunities for a short cruise of this kind are limited.
San Diego Trips  Question:I would like to take a cruise of three days or so from San Diego down the coast of Baja California, Mexico. If there is such a cruise, on a small ship, who administers it? - Z. C. M., New York, N.Y.  Answer:Opportunities for a short cruise of this kind are limited. One option is the Executive Explorer of Catamaran Cruiselines which does four-night round trips from San Diego with an overnight in Ensenada, Mexico. Among other places visited are Anacapa and Santa Catalina Islands. This cruise will be available on the 104-foot-long vessel, which carries 49 passengers, in April and May.
Fares range from $559 to $859 a person, double occupancy. The Executive Explorer also does three-night cruises but these do not go to Mexico. From June the ship is scheduled to cruise to Alaska. (Catamaran Cruiselines, 1620 Metropolitan Park Building, Seattle, Wash. 98101; 206-623-2417 and 800-622-2042.) Visitors may also go down to Ensenada on a day trip aboard the Lucille operated by Ensenada Express (Post Office Box 81823, San Diego, Calif. 92138; 800-422-5008 in California, and 800-826-4815 out of state). They can also arrange to stay in Ensenada for one or more nights and return on the Lucille. The 120-passenger ship's departures are daily Friday through Monday until Memorial Day and then seven days a week. The journey takes three and a half hours, each way; five hours are spent in Ensenada. The round-trip fare is $59 until Memorial Day, then $79.
Baja Frontier Tours (2223 C Street, San Diego, Calif. 92102; 619-232-1600) will arrange accommodations in Ensenada for Ensenada Express passengers. At the Quintas Papagayo Beach Resort about a mile north of downtown, a studio room for two costs from $37 a night, and there are oceanfront rooms and villas at prices up to $80. Rates for two at the downtown San Nicolas Resort Hotel are from $82.70. Baja Frontier Tours also arranges cars with drivers, and accommodations in Loreto, Cabo San Lucas, La Paz and other towns in Baja California.  Customs Rules  Question:If I buy expensive items in duty-free shops in Martinique, will they be exempt from duty on returning to the U.S.? I am taking my new foreign camera. Could that be a problem with customs inspectors? -V. W., Syracuse, N.Y.  Answer:Anything American travelers purchase in duty-free shops overseas is subject to duty when they return home. But all purchases, including those bought in duty-free shops abroad, can be included in the exemption allowance granted to everyone who has been out of the United States for 48 hours. (People visiting Mexico or the U.S. Virgin Islands need not be out of the country for 48 hours to qualify for the exemption.) Each returning traveler is allowed to bring in $400 worth of goods free of duty (or $800 from the U.S. Virgin Islands). The exemption is allowed each time travelers return to the U.S., but 30 days must elapse before they qualify for another.
The description of airport and other stores as duty-free in Martinique and other islands indicates the absence or reduction of import duty that might otherwise have been applied in that country.
Generally, U.S. Customs inspectors are experienced in determining whether an item was purchased abroad or in this country. But to avoid a problem over the new camera, it is advisable to carry the receipt to prove it was purchased in the United States or on an earlier trip abroad. An alternative is to register the camera with the Customs Service at an international airport, or at a district Customs office, before traveling.  Portuguese Route  Question:How long is the drive from Lisbon to the Algarve, and can you suggest places to stay on the route? - B. S., Elkins Park, Pa.  Answer:The drive from Lisbon to Lagos at the western end of the Algarve, which extends eastward to the Spanish border, can be done in about five hours. The distance along this route, close to the Atlantic coast, is about 160 miles. There are many atractive villages and fishing ports with small inns - but no major hotels - along the way. The traveler might want to consider the small pousadas, or government-run inns, which all have restaurants, on the route. There is one, the Sao Filipe, in Setubal, although this is only about 30 miles from Lisbon. Farther south are the Pousada de Vale de Gaio in Alcacer do Sal and the Santiago in Santiago do Cacem, each with seven rooms.
Some drivers prefer to drive inland from Lisbon to Evora before heading south to the Algarve via Beja. The 32-room Pousada dos Loios in Evora, a city that reminds many visitors of Andalusia, is in a former monastery.
Rates at the governmemt-run inns generally range from $47 to $55 a night for two, including Continental breakfast. The Portuguese National Tourist Office in New York (212-354-4403) has information on making reservations for hotels and pousadas.  Theme Parks  Question:Is there a list of all the theme parks in the United States, with admissions and driving directions? - P. C. H., Winter Park, Fla.  Answer:It may not be possible to find one source giving all this information but there are publications that go part of the way. Rand McNally's Family Adventure Road Atlas ($7.95) includes a map showing a dozen theme parks across the country that is keyed to a list of details on each park. The Rand McNally Road Atlas & Vacation Guide to the United States, Canada and Mexico ($12.95) gives a list of recreational sites, including theme parks, above each state map. The Birnbaum guidebook called 'United States' ($12.95) includes a list of 18 theme parks and Fodor's 'U.S.A.' gives details of several. The Complete Traveller Bookstore in New York (212-685-9007) and Travel Books Unlimited in Bethesda, Md. (301-951-8533) are among stores that carry these publications.
'The 1988 Directory of Theme and Amusement Parks,' a revised version, includes 450 listings, state by state, with brief infomation on each park but not rates or directions. The 56-page book is available from Pilot Books (103 Cooper Street, Babylon, L.I. 11702; 516-422-2225) for $3.95 and $1 for postage.