The U.S. Virgin Islands are balmy year-round, but rates are about one-third as expensive in sum-mertime: Spend four days and three nights in St. Croix at the plush Carambola Beach Resort for $690, including round-trip airfare from Washington, D.C., through August 25. (From Chicago, the rate is $790, Los Angeles, $930.) You can mountain-bike, horseback-ride, hike, or dive from your villa. (Scubawest, at 800-352-0107, charges $75 for two-tank dives.) Packages must be booked by June 31 through Future Vacations at 800-456-2323 or www.futurevacations.com.
One week, two friends, seven islands, $960. Now through October, Idaho-based outfitter Remote Odysseys Worldwide (800-451-6034; www.rowinc.com) reduces rates by 25 percent per person on its Greek Discovery Cruise—if you share a cabin aboard the 112-foot yacht with two others. You'll sail to and hike the rocky terrain of Tinos, Naxos, and Ios, among others.
Even in June, weather in north-central Maine can be a crapshoot, which is a boon for whitewater rats. Just when the Penobscot River surges with dam-released winter runoff, North Country Rivers (800-348-8871; www.ncrivers.com), based in East Vassalboro, Maine, slashes its rates. Weekday trips on the Class III, IV, and V Penobscot run $67 per person all month; Saturday slots, $87—compared to $127 per person in July.