Hot Commodity: DropletsAmount of earth's surface covered in water: 80%
97% of the earth's water is saline
Water that is frozen in glacial ice: two percent
Only 1% of the earth's water is fresh and available for human use
153 GALLONS (water used daily per capita in the USA)
88 in the UK // 23 in Asia // 12 in Africa
Sources: U.S. Environmental Protection Agency; National Wildlife Federation
1. Raft the Colorado River through the Grand Canyon, Arizona Plunge into 277 miles of Class I-V whitewater and spectacular red rocks. Get on the 12-year waiting list for individual permits (800-959-9164, www.nps.gov/grca) or sign up with an outfitter like Canyoneers Inc. (800-525-0924, www.canyoneers.com).
2. Paddle the Boundary Waters Canoe Area Wilderness, Minnesota Nearly a thousand interconnected lakes and streams dot this million-acre north-woods wilderness. For maps and permits, contact the BWCAW (877-550-6777, www.bwcaw.org).
3. Snorkel in Dry Tortugas National Park, Florida Set sail for seven white-sand islets and miles of coral reefs in the Gulf of Mexico. Go with Ocean Voyages (800-299-4444, www.oceanvoyages.com).
4. Learn to Surf at Waikiki Beach, Hawaii It's a kitschy and overdeveloped beach, yes, but punch your surf ticket on the slow rollers off Oahu's leeward shore before braving Pipeline. Check out Hans Hedemann Surf School (808-924-7778, www.hhsurf.com).
5. Sea-kayak the San Juan Islands, Washington Island-hop among the orcas. Call Outdoor Odysseys (800-647-4621, www.outdoorodysseys.com).
6. Paddle the Middle Fork of the Salmon River, Idaho Float 100 miles through the Frank Church-River of No Return Wilderness. Check out Middle Fork Wilderness Outfitters (800-726-0575, www.idahorapids.com).
7. Sail the Maine Island Trail, Maine Explore spruce-shaded islands and craggy coastline on this 325-mile route from Portland to the Canadian border. For details, contact the Maine Windjammer Association (800-807-9463, www.sailmainecoast.com).
8. Raft and Fly-fish the Talkeetna River, Alaska Fish for king salmon, then hunker down for a 14-mile Class IV ride. Go with Keystone Raft and Kayak Adventures (907-835-2606, www.alaskawhitewater.com).
9. Canoe the Okefenokee Swamp, Georgia Float between gators in southeastern Georgia's lush 400,000-acre wilderness. The Okefenokee National Wildlife Refuge (912-496-7836, www.fws.gov) can provide details.
10. Kayak the Apostle Islands, Wisconsin Paddle around 21 unspoiled Lake Superior islands. Try Piragis Northwoods Outfitting (800-223-6565, www.piragis.com).