Dawn. Waves of turquoise blue Caribbean lap over your kayak as you paddle along Palancar, the world's second-longest barrier reef. Beneath you, 68 varieties of coral spiral like submerged rainbows. Overhead, roseate spoonbills, pelicans, and birds beyond description wing to the million-acre jungle of Sian Ka'an. Outfitters like Adventures in Perspective (715-779-9503; www.livingadventure.com) offer trips to the Yucatan Peninsula focused on Mayan culture, birding, and just plain fun in the sun along sandy beaches and pristine jungles. For more information on the Sian Ka'an Reserve and other locations in the Yucatan, log on to www.planeta.com.