Like airlines and hotel chains, cruise lines invite repeat customers to join their reward programs. Points are scored for each cruise (or cruise night) a passenger books on the same line; as points accumulate, the value of the perks rises — from exclusive cocktail receptions and loyalty club lapel pins all the way up to free cruises. Joining an elite program is free. Nearly every operator has its own version, including the top premium and luxury lines, but how much sailing does it take to reap a sought-after reward?

In any frequent-cruiser program, the emphasis is firmly on frequent. Most reward programs kick in (often automatically) on a passenger’s second cruise, but in these early stages, the perks are rather slim. Members of Regent Seven Seas Cruises’ loyalty program, Seven Seas Society, for example, qualify for a members-only cocktail reception after seven nights sailed. On Cunard Cruise Line, which originated a program rewarding its loyal passengers in the mid-19th century, two voyages or 20 nights sailed convert to two free hours on the Internet and a special cocktail party for its World Club members. Members of the Viking Explorer Society are feted at a members-only cocktail party on their second and all subsequent voyages on Viking River Cruises.

While no frequent-cruiser program offers points for dollars spent on your credit card, three lines allow for some reciprocity. Benefits accrued through Royal Caribbean International’s loyalty club, The Crown & Anchor Society, can be claimed aboard Celebrity Cruises and Azamara Club Cruises. All three lines have their own reward clubs, each with multiple tiers and some unique awards along the way (such as behind-the-scenes tours), and all top out with what frequent cruisers prize most: a free cruise. On Royal Caribbean, a free seven-night cruise is reached at the 700-point level (350 nights sailed in a suite, 700 in other classes), while on pricier Azamara Club Cruises and Celebrity Cruises, the threshold for a free cruise requires slightly fewer days at sea.

Oceania Cruises’ rewards program, Oceania Club, includes a free seven-day cruise after 20 cruises. Members of Silversea Cruises’ Venetian Society qualify for a free week’s cruise after 350 sailing days. Perhaps the quickest way to a free cruise for frequent sailors on any luxury cruise line is offered by Crystal Cruises, which awards members of its Crystal Society a complimentary seven-day cruise after as little as 13 extended voyages (of 16 days or more each).

So while it’s clearly a long stretch from free cocktails to free cruises, frequent-cruiser programs do pay off, albeit only with a sweet perk or two for all but the most frequent passengers.