This chain, due west of Sardinia in the Mediterranean Sea, exists in the shadow of more popular European charter routes. The Balearics are not a place you typically cruise to (unless 20 hours under way from Antibes is your idea of a vacation); they are a place you fly to and explore. Menorca, to the east, promises splendid hiking and wildlife. Ibiza, to the west, is renowned for its discos and nightlife. Between them is Mallorca, an island with enclaves for the wealthy and famous, but which mostly is bent on upgrading its middle-class tourism image as destinations such as Croatia and Turkey take over the "value label for European travelers. Britons and Germans flock to Mallorca during the summers, staying in less-expensive resorts than are usually available on the French and Italian coasts. The harbors around Palma, the capital, are abuzz with 40- to 60-foot Fairlines and Sunseekers, but the only large yachts that tend to stay for any length of time are in the local yards, gearing up for another season around Corsica or St. Tropez.