The Clipper Cruise Line, the sailing ships that also serve as cruise ships, is offering a deal according to Frommers.  

Soft-adventure operator Clipper Cruise Line (tel. 800/325-0010; www.clippercruise.com) is offering discounts, including deals for single travelers, for a handful of itineraries in 2005 and 2006 in the Caribbean, Antarctica, Artic, Russian Far East, Southeast Asia and other regions. Double occupancy rates are lowered up to $4,000 (per cabin) and singles can save as much as $5,145 on a number of cruises aboard Clipper’s four small globe-trotting ships, the Nantucket Clipper, Yorktown Clipper, Clipper Adventurer, and Clipper Odyssey.(read more here)