The Baja Coast along the Sea of Cortez offers treasures to the intrepid traveler by Tom Gatch Situated at upper end of the Sea of Cortez , the eastern coastline of northern Baja California supports an entirely different type of habitat and marine life profile than does the Pacific side.  Rugged volcanic outcroppings and occasional groups of small, rocky islands intermittently interrupt the many miles of warm, sandy beach that adjoin a tepid desert sea.   The narrow highway south of San Felipe that eventually meets the small settlement of Puertecitos some 50 miles away, runs parallel to long stretches of unpopulated beach.  The inshore waters nearby …