"The per diems are often half of what you'd pay for a regular cruise," Laign said, "and they tend to have itineraries with ports of call not regularly visited."
Because these trips have many more days at sea than a standard cruise, they tend to appeal to seasoned travelers who "really like to sail," he said, "cruise veterans who are looking for something a little different."
Mike Driscoll, editor of cruise industry newsletter Cruise Week, says that with long stretches of sea time between ports, these are trips "where you want to bring your 1,000-page Ken Follett novel."
If you can't spend a full 14 days afloat, are you out of luck? Not necessarily. While Carnival requires that its repositioning passengers book the entire trip, policies of other cruise lines vary. Some allow passengers to book segments as short as a single day.
Saunders cites the example of a 17-night cruise departing Vancouver Sept. 25 for San Diego by way of Hawaii. Passengers can book the whole trip or just, say, the one-day jaunt between Vancouver and Seattle.
Hankamer, of Vacations To Go, says he's seen per diems as low as $35, "and that includes all meals, entertainment, and your room."
His site lists some 27 upcoming repositioning cruises, all scheduled for September to November. He says that while the popularity of these cruises has increased, so has the number of ships, which has kept prices from rising.