In many ways, cruising is an ideal getaway for solo travelers. Many cruise lines welcome singles with receptions to meet other solo passengers, usually held early on in the cruise. Some even have "gentlemen" dance hosts onboard so that women traveling alone do not feel like wallflowers when the band strikes up. These dance hosts can be found on Crystal, Cunard, Fred. Olsen and Voyages of Discovery (November to April only). On longer voyages of Holland America (30+ days) and Silversea (10+ days), similar services are also offered. Seabourn makes sure all single travelers are hosted at dinner by the ship's officers, staff or entertainers. And, with themed cruises on the rise, solo travelers can choose to book onto group sailings targeting singles.
If you're contemplating cruising on your own, what do you need to know before booking a voyage? Here are the four key factors you should consider:
The industry's trend toward bigger and bigger ships -- think 5,400-passenger Oasis of the Seas -- makes it a bit harder to meet others who may be traveling alone (a bit like the difference between living in a small village and Manhattan). It can be more difficult to find these fellow solo passengers on ships with thousands of guests, and you're not guaranteed to run into friendly folks you meet on a shore excursion or at the casino later on in the cruise.
Small ships, on the other hand, tend to be quite social, and you'll see the same faces again and again. Open-seating dinners, smaller excursion numbers and an emphasis on interactive activities (like game play and trivia) are conducive to meeting people and making friends. However, these ships tend to carry an older clientele and a higher price tag, so they might not be what young, single travelers are looking for.
Beyond the size of the ship, another consideration for solo travelers is cabin type. Newer ships tend to feature uniform, pre-fabricated cabins for two, so there are fewer single cabins to be found. Illustrating this trend, while Cunard's now-retired QE2 was built in the late 1960's with 122 single cabins, neither the 2004-launched Queen Mary 2 nor the new-for-2010 Queen Elizabeth offer cabins for one.
The good news is that 2010 may be a banner year for solo cruisers. P&O Cruises' Azura debuted in April 2010 with 18 dedicated single cabins, a first for the U.K.-based line. But, the real story is Norwegian Epic -- 2010's massive NCL new-build. The ship features 128 cabins designated for solo travelers. The so-called "studio cabins" are 100-square-foot accommodations with full-size beds and separate areas for the bathrooms, sinks and showers. Studio passengers also get an exclusive, shared social space called the Studios Lounge, featuring a bar, two large TV screens and a concierge for booking dinner reservations and shore excursions. All 128 of the studio cabins will be priced for single occupancy.
Older ships with single cabins include the following:
Costa Cruises offers single cabins -- or regular cabins priced for solos -- on most ships, especially the older ones, but they're only available to Europeans -- not to North Americans.
Swan Hellenic's Minerva, another older ship, has nine solo cabins, but 30 to 40 additional staterooms are designated for solo travelers, depending on the demand for each specific cruise.
Saga Holidays is one of the few companies offering single cabins in a variety of categories; Saga Ruby offers 92 single cabins, and Saga Pearl II has 60 single cabins -- for each ship, that's almost 25 percent of the total number of cabins.
Another exception is Voyages of Discovery; while MV Discovery has only two dedicated single cabins, a limited number of double cabins are also designated as singles and sold at a singles rate. As an added bonus, all travelers in solo cabins are invited to a cocktail reception early in the cruise to meet other single cruisers.
All Fred. Olsen ships -- Balmoral, Boudicca, Braemar and Black Watch -- offer solo cabins, ranging in number from 40 (Braemar) to 64 (Balmoral). Cabins come in a variety of categories, including a few balcony cabins and solo suites. One nice touch offered by Fred. Olsen is that single cabins are actually decorated for solos; instead of simply giving a lone passenger a cabin with two beds, staffers remove one bed and replace it with other furnishings for a cozier feel.
In addition, river cruise lines tend to be very welcoming to solos, often offering discounted solo rates.
Since upscale lines tend to offer price breaks to solo cruisers more often than the mainstream lines, you may find that cruising on a luxury ship with a minimal supplement is a better value than sailing on a mass-market ship with a heavy supplement.
Keep tabs on the latest solo "sales." Many cruise lines offer price breaks on occasion, depending on the season and on how many cabins are booked on individual ships. Some deals we've seen recently include no single supplement on spring South Pacific cruises onboard Paul Gauguin or seven-night Greece cruises on the luxury yachts of Variety Cruises. Uniworld removed single supplements for travelers who booked 2010 Europe river cruises on the early side, and Oceania offered a reduced supplement for guests who booked well in advance. These offerings can change from week to week, so keep checking back, or sign up for cruise line e-mail alerts to find out about the newest promotions.
Here's a tip: If you can be very flexible about your travel plans, some cruise lines may extend last minute solo discounts on close-in sailings. They're not always well-publicized, so be sure to ask your travel agent if there are any sales currently. Also check the Cruise Critic Solo Cruisers and Singles Cruises forums for news of the latest solo deals.
Consider sharing a cabin. Sharing a cabin with a stranger may not appeal to everyone, but it does mean savings. Fewer lines are offering roommate matching services than in the past, but Fred. Olsen and Holland America still try to match up solo travelers. You ask to be paired with a roommate when you book, and if the line can match you with another solo passenger of your sex, you will pay no extra supplement. However, if no match is available, the supplement still applies.
Here's a tip: If you are interested in finding a roommate and the cruise company cannot help, you might have luck with matching services, such as travelchums.com, which pairs travel-minded single people for a fee. Members of these services post their travel plans and information about themselves, and it is up to each member to contact those who sound like compatible companions. Alternately, look for travel-related message boards -- some of these allow people to post that they're looking for someone to travel with them.
SinglesCruise.com (800-393-5000) is the largest of these, averaging a cruise per month for 100 to 400 single passengers. They offer to match you with someone of your sex and smoking preference, but they make no guarantees on compatibility. If they cannot make a match, the single supplement will apply.
VacationsToGo.com (800-338-4962) now offers singles cruises featuring exclusive cocktail parties, mixers, games, group excursions, single-mingle dining and more. They even offer roommate matching to avoid the single supplement. Once you've reserved your cruise, you'll get private access to a chat site where you can get to know other Vacations To Go singles before you set sail.
Singles Travel International (877-765-6874) offers group cruises for singles, featuring the services of a tour director, exclusive parties and cocktail hours, singles-only seating in the dining room, and optional "singles tours" in every port. Travelers can request single cabins (for an extra charge) or get matched with a roommate; if the company can't find a roommate for you, it will cover the cost of the single supplement. Its Web site also has a community section where travelers can get to know each other and find roommates prior to their cruises.
Escapade Cruises & Tours (888-775-0288 www.singlescruises-tours.com) is an agency that specializes in travel -- including cruises -- for singles and solos. Osolomio.com (800-959-8568) is another large singles tour specialist with cruises among its offerings.
Solo's Holidays (0844 815 005) is a U.K.-based travel agency that caters to singles. The company specializes in organizing groups on a variety of cruises, from niche Nile river cruises to mainstream vessels. The site offers online booking, and fares are simply priced on sole occupancy or sharing a cabin with another Solo's group member. Many of the trips include a group leader.
Get involved. The best way to meet people onboard is to take part in activities, so choose a cruise ship offering things you like to do (beyond the de rigueur singles' social), such as intriguing programs, classes or workshops. In that arena, two standouts are Cunard's QM2 -- which has teamed up with Britain's Oxford University, Royal Academy of Dramatic Art (RADA) and Royal Astronomical Society to offer a wide array of courses, workshops and speaker series -- and Crystal Cruises, which has an outstanding overall series, featuring language, music and art programs, as well as compelling guest lecturers.
Make friends with the cruise director. If you tell the cruise director you want to meet other singles onboard, he may be able to help with introductions.
Try the piano bar. Sociable sing-alongs are a good way to make friends. A veteran cruiser also suggests visiting the bars and lounges onboard the first night at sea. That's when other singles are most likely to be roaming to see who is onboard, she says, and if no one is around, they may not return.
Choose compatible dinner partners. If you opt for traditional onboard dining (with an assigned dining time and table), you will be seeing your dinner companions every night, so it is important that you enjoy them. Do not be shy about asking a maitre d' for a new table if the passengers at your original seating aren't compatible. Often, requests to be seated with other solo cruisers will be honored if possible. Also, most families choose early dining, so opt for a later seating to find more like-minded dinnermates. If you've chosen a flexible dining plan, request to be seated at a table with other diners, if possible, rather than eat alone.
Take the ship's shore excursions. This is my favorite tried-and-true way to meet others; the wackier the excursion, the more likely there will be a bonding opportunity.
Connect with your shipmates pre-cruise. Cruise Critic's Roll Call threads allow travelers on the same sailing to get acquainted and plan excursions, happy hours and dinners together -- before they even embark on the ship. You'll come onboard feeling like you already know people on the ship. Plus, you can sign up for Meet & Mingle parties on Azamara, Celebrity, Royal Caribbean and Crystal to meet other Cruise Critic members onboard your ship.
Hand out calling cards. This is a great tip for a solo trip on a mega-ship, where it can be easy to lose a potential friend in the crowd. You may meet someone you'd like to see again, but never run into them by chance. If you make up cards with your name and cabin number and hand them out to new acquaintances, they will know how to reach you to arrange to get together again.
Choose a theme cruise. In addition to dedicated singles cruises, theme cruises -- focusing on topics like music, dance, politics, wellness and sports or film stars -- are a great choice for solo travelers. These chartered sailings feature a wide range of mixers, activities and lectures for participants and often have support staff onboard to facilitate events. The exclusive onboard activities are a great way to meet people, and you have an easy conversation starter since you know that everyone shares at least one common interest.
The good news is that 2010 may be a banner year for solo cruisers. 
The biggest hurdle for solo cruisers is the dreaded single supplement. Because most lines don't offer cabins for one, or because the few that exist sell out quickly, they will typically charge an extra fee to a solo traveler who wants to reserve a double-occupancy cabin sans roommate. This surcharge can range anywhere from 10 percent of the cruise fare to 100 percent (which, in essence, means you are paying double or the same price as two people sharing a cabin). 
There's an art to traveling singly -- and happily. Unless you're cruising solo to get away from people, here are some suggestions for mixing and mingling. 