A question I am frequently asked is, what, exactly, is a "single supplement?"

In a nutshell, it is the price you must pay for requesting a single cabin, which seems like a penalty for cruising solo. In fact, that's exactly what it is, because the cruise lines want to make up for the revenue lost by that empty bed in your cabin. And not just for the price of that cabin -- one less passenger onboard means one less person buying drinks, souvenirs, shore excursions, etc. So the cruise lines make up for that, in part, by charging that dreaded "single supplement."

Some ships do have cabins for single-occupancy available. These are more common on older vessels due to irregular cabin configurations that were designed to fit the shape of a ship's hull. Cabins on contemporary ships are mostly uniform, constructed in a modular design and installed after the hull is afloat. So, with most cabins designed for two people, the cruise lines charge the supplement, which is generally stated as a percentage of the per-person, double occupancy rate.

One way around paying the single supplement is the "guaranteed share plan," something that is offered by several cruise lines. You agree to share a cabin and are charged the per-person, double occupancy rate. If no cabin mate is found, you have it all to yourself and do not pay anything extra. Be aware, however, that you will only be matched by gender, not age or smoking preferences. Sometimes the share plan works quite well, and you might find a lifelong friend, as well as a future cruising companion. On the down side, you might be so miserable you will want to sleep outside in a deck chair, because rooming with a stranger is always a crapshoot.

The chart below lists the policies of the major cruise lines as to the supplements they charge and whether they offer a guaranteed share program. When booking, always ask about any specials currently being offered. Radisson Seven Seas recently had a rate of only $99 for their single supplement. In addition, rates will sometimes vary according to category, and prices may also drop close to sailing date, because ships do not like to sail with empty cabins.

Cruise Line	Single Supplement	Guaranteed Share Plan
American Canadian Caribbean Line	175-200%	Yes
American West Steamboat Co.	150-200%	No
Bergen Line	Varies	Yes
Cape Canaveral Cruise Line	Varies by season	No
Carnival Cruise Lines	150-200%	No
Celebrity Cruise Lines	200%	No
Clipper Cruise Lines	Varies	Yes
Costa Cruise Lines	150-200%	No
Cruise West	150%	Yes
Crystal Cruises	125-150%	No
Cunard Line	175-200%	No
Delta Queen Steamboat Co.	150% and up	Yes
Disney Cruise Line	150-200%	No
First European Cruises	150-200%	Yes
Holland America Line	150-190%	Yes
Norwegian Cruise Line	Varies up to 200%	No
Oceania Cruises	175-200%	No
Orient lines	105-200%	Yes
Princess Cruises	125-200%	Yes
Radisson Seven Seas	125-200%	No
Royal Caribbean International	200%	No
Seabourn Cruise Lines	110-175%	No
Silversea Cruises	150% - varies	No
Star Clippers	150%	No
Swan Hellenic	Varies	Yes
Windjammer Barefoot Cruises	175%	No
Windstar Cruises	175%	No