If cruising to the desert sounds like a physical impossibility, consider the Sea of Cortez -- a region where an environmental phenomenon has made the impossible possible. It's where the desert meets the sea -- literally.
More than 50 desert islands dot the 700-mile sea.
Millions of years ago, a shift in the San Andreas fault ripped what is now Baja California from the flank of mainland Mexico. When the Pacific rushed in to fill the gap, it created the Sea of Cortez, or the Gulf of California. Volcanic activity thrust up into this body of water an array of islands that receive so little rain that their landscapes have become deserts.
Each isolated island has produced unique ecosystems and wildlife over millions of years, much like the Galapagos.
Author John Steinbeck, who studied marine biology at Stanford University, found these islands so fascinating that he sailed a sardine boat there in 1940 with a biologist friend to collect marine invertebrates. He wrote about the trip in his book "The Log From the Sea of Cortez."
A half-century later, these islands still belong to the wildlife. Today, from an anchored ship, passengers can take a tender ashore to spend whole days exploring uninhabited islands that harbor unique species.
Conscientious eco-tourism and the Mexican government have helped to preserve these habitats. Island stops are regulated by the Mexican government, which since 1978 has declared 47 of the islands wildlife refuges.
Here are some Sea of Cortez cruises:
* Clipper Cruises' 138-passenger Yorktown Clipper sails an 11-day cruise on Nov. 13. Cruise-only fares start at $2,450. Shorter cruises depart April 16 and April 23. For information, call (800) 325-0010.
* Special Expeditions sails variable-length Sea of Cortez itineraries in December and January on the 70-passenger Sea Lion and Sea Bird. Fares start at $2,350. For information, call (800) 762-0003.
* Baja Expeditions, a small California outfitter, specializes in Sea of Cortez trips with itineraries that offer a taste of Steinbeck's island-hopping journey. It sails an informal 80-foot, 14-passenger expedition vessel, the Don Jose, on 10-day cruises between La Paz and San Felipe. Fare for the April 20, 1996, and May 1, 1996, departures is $1,795. For information, call (800) 843-6967.
* If you enjoy traveling with birds of a feather, consider hooking up with groups from the natural-history network of museums and environmental societies that buy space on some ships to sell to members.
The Massachusetts Audubon Society, for example, usually reserves about half the cabins on designated Sea Lion departures. Fares start at $2,990. For information, call (800) 289-9504.