Southern Baja’s Espiritu Santo Island, in the Sea of Cortez, is known as the Mexican Galápagos for its abundance of marine life, from dolphins to manta rays. And the Espiritu Santo Island Circumnavigation trip offers a chance to sea kayak, snorkel, and camp on the island’s sparkling beaches. Go in fall and you’ll avoid summer’s heat and winter’s strong winds; it’s also a time when the Baja desert is blooming and the water is warm and clear—just right for snorkeling. Between excursions you’ll hike through canyons and boulder up arroyos, surrounded by cacti, hanging fig trees, and Baja “lace”—where pink volcanic ash drips from the cliffs. At Los Islotes, a sea lion rookery, travelers get to swim alongside the local inhabitants.