Are Seabourn and Crystal Cruises the world's best cruise lines? That's the word this week from Travel & Leisure, which is out with its closely-watched World's Best Awards for 2011.

Derived from a survey of Travel & Leisure readers and published in the August issue now on newsstands, the rankings once again put Crystal No. 1 among large-ship lines with a score of 92.45. Seabourn is tops among small-ship cruise lines with a score of 93.3.

Runners-up among large-ship lines: Regent Seven Seas Cruises (90.14); Oceania Cruises (86.42); Disney Cruise Line (85.70); and Cunard Line (84.27).

Rounding out the top five in the small-ship line category are Silversea Cruises (90.03); Lindblad Expeditions (89.25); SeaDream Yacht Club (88.33); and Windstar Cruises (85.63).

In a separate category for river cruise lines, Tauck came in at No. 1 with a score of 90.06, followed by Uniworld (88.70); Viking (86.76); AmaWaterways (85.23); and Avalon Waterways (84.27) .

Other major lines? The survey gave Azamara Club Cruises a score of 82.51, putting it sixth among big-ship lines just behind Cunard (the two lines flip-flopped positions from last year). Celebrity Cruises was not far behind with a score of 81.92, placing it seventh among big-ship lines. Celebrity scored just a tad better than rivals Holland America (81.29), Royal Caribbean (80.28) and Princess Cruises (79.81).