While those who book their cruise in a more traditional manner instantly receive a cabin assignment, folks who book a guarantee are only promised a stateroom -- somewhere, anywhere on the ship -- in the same category that they've chosen. The actual cabin will not be assigned until sometime after your booking (often a few weeks or days prior to departure).
For more on the traditional way to choose a cabin, see our feature on this topic.
Travelers are guaranteed a cabin in the category they've chosen, but there's always the possibility of an upgrade. The real risk is simply giving up the chance to pick your spot -- midship, high deck, low deck, etc. If you don't get that upgrade (and even if you do), you might end up with the oddball cabin no one wants because it's a strange shape, under a noisy deck or a long trek from the elevator.
As simple as this may sound, guarantees remain something of a mystery to many cruisers. Central to this is the fact that there is no standard method of dealing with them: Each line has its own unique policy that we'll outline below, including how long you need to wait before you get that cabin assignment. But first, we'll address those two burning questions mentioned above:
Will I Save Money? The answer depends on which line you choose. In some cases, even if you don't get an upgrade, you can still save a few bucks. Cunard, Carnival, Seabourn and Costa are among those that sell guarantee cabins at slightly lower fares.
In other cases, there's no real savings; Crystal, Disney and Holland America are among those that told us they permit guarantees, but you'll pay the same as anyone booking a cabin in that particular category. With these lines, you only get a deal if you score that upgrade. Otherwise, you've simply gambled away your right to pick a cabin location.
Will I Get Upgraded? Savings or no, the lure of the guarantee is the possibility of an upgrade -- and it does happen. If you book a guarantee in a certain category and that category is full, you might get upgraded to an empty cabin in a higher category. On the other hand, someone else (perhaps a member of the past-passenger program with higher status) might get upgraded and you might get their cabin in your category. However, a guarantee passenger is more likely to be upgraded than someone of the same status who booked an allocated cabin at the same price.
As there's no way to predict what you'll get, the cardinal rule of booking guarantees becomes: Don't book a guarantee in any given category unless you would be happy with a cabin in that category! In other words, if you will not be happy with anything less than a suite, don't book an inside guarantee.
As obvious as that may seem, I once met a couple whose travel agent convinced them that if they booked an inside guarantee, they were "virtually" assured an upgrade to a balcony cabin. They decided to save the money and book the inside guarantee rather than the balcony cabin they'd planned on. Unfortunately for them -- and perhaps not surprisingly -- they wound up with an inside cabin on the lowest deck, in the category they paid for. Fortunately, the ship wasn't full and they were able to upgrade (and paid plenty for it), but their cruise could nearly have been ruined.
No matter what a travel agent or anyone else tells you, the cruise line is not obligated to give you a cabin in a higher category than you booked. When booking a guarantee, do exactly what you would do when booking an assigned cabin -- book the least expensive category that you will be happy with. An upgrade is a nice surprise, but not something you should count on. (For other ways to improve your onboard digs, see our story on five ways to get a cabin upgrade.)
Ultimately, the decision to go for a guarantee or not depends on your cruise preferences. If the cruise line is offering a guarantee at a lower fare than the least expensive assigned cabin, and you really don't care too much about your cabin, go for it. You are, after all, guaranteed to get at least what you paid for, and you just might be lucky and get that great upgrade. And it does happen ... sometimes.
On the other hand, if you won't save any money by booking a guarantee, you'd probably do just as well by looking at a deck plan and choosing a specific cabin you know you'll be happy with. If you're very particular about location, then a guarantee definitely isn't for you. Only go for this type of guarantee if you're a risk-taker who thrives on the suspense.
For a closer look at guarantees, we asked each major cruise line to detail their own policy on guarantee cabins.
Azamara Club Cruises
How It Works: Azamara Club Cruises offers guarantee cabins if all assigned suites and staterooms are sold out in a particular category. If a room opens up in a higher category than the one you've guaranteed, you'll get that complimentary upgrade.
When You'll Know: Guarantee cabins are typically assigned between two and three weeks prior to departure, although some are assigned the week of sailing.
Carnival Cruise Lines
How It Works: Passengers may either book a generic cabin type (e.g. Inside, Outside, Balcony) at a lower fare than for the lowest specific category within that type, or book a guarantee within a specific category at the normal fare for that category.
When You'll Know: Carnival begins assigning guaranteed cabins from about eight weeks up to a few days prior to sailing. The majority of passengers are notified of their cabin assignment either when they receive their cruise documents (if you've booked over the phone or with an agent) or through your online account (if you've booked online).
How It Works: Celebrity Cruises offers two types of guarantees, both of which are based on availability. Passengers can choose a category type (inside, outside, etc.) and pay a price lower than the regular fares for that category. They will be berthed in a cabin within the chosen category. Or, they can choose a specific category and pay the associated fare (no discount), and be berthed in that category or a higher category.
When You'll Know: Guarantee cabins are typically assigned about one week prior to departure, although some are assigned the week of sailing.
How It Works: Guarantee passengers may either be allocated a generic cabin within the type they paid, or offered a higher category cabin for the same price.
When You'll Know: You can find out your cabin number just a few days before departure, and sometimes on the day of sailing.
How It Works: Crystal Cruises offers guarantees in all categories, except CP (Crystal Penthouse -- the highest category); passengers book guarantees at the same fare as an assigned cabin in that same category.
When You'll Know: Cabin assignments may be made as early as one month prior to departure, or as late as the day prior to departure. Most cabins are usually assigned one week before sailing.
How It Works: Cunard offers guarantees both for generic cabin types at special lower fares and for specific categories at the normal fare within that category.
When You'll Know: Cabin assignments may be made anywhere from 150 to 1 day prior to departure.
Disney Cruise Line
How It Works: Disney Cruise Line offers guarantees in any given category at the normal fare for that category, depending on availability.
When You'll Know: Cabin assignments generally take place within 30 days of departure.
Holland America Line
How It Works: Holland America Guarantees are offered in specific cabin categories on an as-needed basis, at the normal fare for that category.
When You'll Know: Assignments are made between 30 days and one week before sailing.
How It Works: MSC Cruises offers guarantee cabins selectively based on inventory management restrictions. Guarantees are not available for all categories on all sailings, and are offered by category and type (single, double, triple or quad). Note that on some European sailings, guarantee passengers may be assigned to more than one cabin within a single trip and have to move their belongings to a new cabin partway through the cruise.
When You'll Know: The time frame for assignment of guarantees can vary according to the sailing, category and type of guarantee. In general, guarantees are assigned within two to three weeks of sailing and in some instances may not be assigned until embarkation.
Norwegian Cruise Line
How It Works: Norwegian's guarantees are offered for a stateroom in the category the guest initially paid for, or possibly a higher category.
When You'll Know: Assignments are made any time after final payment has been received, up to the day of sailing.
How It Works: Guarantee cabins are offered within specific categories at the prevailing rate, once all available cabins in that category have been assigned.
When You'll Know: Oceania Cruises' cabin assignments are done as soon as accommodations open up. It could be the day after the reservation is made, after final payment is due or even upon embarkation.
How It Works: Depending on availability, Princess Cruises offers guarantees within specific categories as an alternative to an assigned cabin.
When You'll Know: Cabin assignments may be made at any time between the time of booking and several days before departure.
Regent Seven Seas
How It Works: The category and pricing depends on the sailing. Sometimes RSSC is able to offer guests a guarantee cabin at the lowest cost if there is enough availability.
When You'll Know: Cabin assignments are usually made just before departure, anytime from one week up to the day of.
How It Works: Royal Caribbean offers guarantee cabins, based on availability. Prices are traditionally on par with the rates for assigned cabins within the same category.
When You'll Know: The timing varies, but cabins assignments are generally made four to six weeks prior to sailing, although some are assigned the week of departure.
Seabourn Cruise Line
How It Works: Seabourn occasionally offers guarantee fares as a special promotion on select departures. They are typically offered as a "run of ship" guarantee at a flat fare for all suite categories except the larger Classic and Owners Suite categories.
When You'll Know: Guarantees are typically assigned about a week prior to departure. Seabourn points out that when passengers choose a guarantee fare, they probably aren't worrying about what suite they get -- they're all great!
How It Works: Silversea Cruises offers guarantees if all assigned suites are sold out in a particular category.
When You'll Know: A suite may be assigned at any time before departure.
How It Works: Windstar offers guarantee cabins if all assigned suites and staterooms are sold out in a particular category. If a room open ups in a higher category than the one you've guaranteed, you'll get that complimentary upgrade.
When You'll Know: Cabin assignments could be made as late as the day of sailing, but normally they are made much earlier.
--Updated by Erica Silverstein, Features Editor