Arcadia, pictured sailing into Sydney Harbour, has the first new single balcony cabins in the P&O Cruises fleet. Picture: James Morgan

Ships' cabins are decked out for doubles. But the cabin is a haven - your private home at sea, a place to sleep and relax. And if you're a single traveller, it might not work for you to share with an unfamiliar person. In most cases, cruising alone in a double cabin will see you pay a hefty single supplement. This is imposed to try to make up lost revenue, or "spoilage" as it's called in cruising - an empty bed means one less fare and lost income from drink and food sales, the casino and shore excursions.
But more of us are travelling alone, particularly older travellers, many of whom enjoy cruising. And some cruise companies are slowly making changes in an attempt to accommodate the single traveller.
When Cunard launched Queen Elizabeth in 2010 with nine single staterooms, it became the first vessel in the fleet to offer these since QE2 was retired in 2008. Cunard has long attracted solo cruisers with the income to pay the single supplement and the company attempts to cater for those who wish to dine alone or will seat them with other singles. Across the fleet, it employs "gentleman hosts" who will partner women who wish to dance. This is particularly useful on Queen Victoria, which has one of the biggest ballrooms at sea.
To give an indication of how the single supplement increases the price of a cruise, I've compared standard inside cabin fares on a seven-night Queen Mary 2 transatlantic crossing from New York to Southampton in July. For two people sharing (twin share) the fare is $1479 per person. But one person cruising alone will have to pay a single supplement of $1110, taking the fare to $2589 - or 168 per cent of a twin-share fare.
Norwegian Cruise Line made waves in 2010 when it launched the 4100-passenger Norwegian Epic, the first ship with single studio cabins. There are 128 of these spread over two decks, and each has a full-size bed and ensuite. Guests also have access to a solo lounge, The Living Room, where they can mix with other singles. These cabins sell out well ahead of each cruise - they are in the region of $1000 for a seven-night cruise - and NCL has added them to its newest ships, including Norwegian Getaway, which was launched in January with 59 solo studios, while Norwegian Escape, due in October next year, will have 82 solo studios.
There was something in the water around the turn of the decade, for P&O Cruises mega-ship Azura also made a splash in 2010 when it launched with 18 solo cabins which have been snapped up well in advance of every cruise since. Fleet-mate Arcadia is a frequent visitor to Australia and arrived here in March fresh from a multimillion-dollar makeover which gave it more restaurants as well as the first new single balcony cabins in the fleet. P&O claims Britannia, due in 2015, will have more purpose-built solo cabins than any other ship. Aurora has 18 solo cabins and, along with Ventura and Oriana, will also have a handful of staterooms regraded as single balcony, inside or outside. In addition, each will have twin cabins available for single travellers with a smaller supplement.
Pearl Seas Cruises will launch Pearl Mist next month. The US-based ship will carry just 210 passengers on itineraries around the Americas and will have 12 solo cabins. Lone passengers can book double cabins and pay between 150-175 per cent of the double- occupancy rate depending on the stateroom class.
Sister company Azamara Club Cruises will arrive in Australia for the first time in 2015 when 694-passenger Azamara Quest sails from Indonesia. The boutique cruise line offers a small single supplement of 125 per cent of a twin-share fare on selected voyages for those who would rather have their own cabin.
Luxury line Silversea doesn't have solo cabins but does run specials that significantly reduce the single supplement, going as low as 125 per cent of a twin-share fare and providing dance partners on longer cruises. The same is true of Crystal Cruises, which often has singles dinners.
Holland America's MS Prinsendam has three solo cabins and the company's Single Partners Program allows solo travellers to share a cabin with another traveller of the same sex or, if one is not available, pay the agreed- upon double occupancy fare. On each ship, there are more than 40 on-board activities geared towards passengers cruising without a partner.
Fred Olsen Cruises principally sails from the UK but sometimes visit Australia on circumnavigations and all of the ships in its fleet have between 40 and 64 solo cabins.
MSC Cruises offers a single supplement of between 50 and 100 per cent of a second fare on selected itineraries from Genoa and Venice.
Those seeking solo fares are much more likely to find them with the help of a travel agent, in person or online; they have access to offers often not quoted on cruise line websites.
The Australian-based Companion Cruising website specialises in cruising deals for the solo passenger, allowing travellers to register details such as age, gender and where and when they would like to visit before attempting to pair them with a suitable match, thereby avoiding single supplements for both. There's also a companion search noticeboard listing travellers looking for a cruising partner and information about which itinerary they're embarking on. And there are details of available cruises with solo cabins and selected itineraries that have no single supplement.
Cruise Express has a dedicated area called Your Solo Zone which lists cruises with reduced single supplements and waivers. A seven-night cruise on Norwegian Epic round trip from Rome throughout June and July is listed from $1171 in a studio cabin. The company also has fully escorted group tours on which singles can get to know each other.
A glance at cruiseabout.com.au shows dozens of solo cruising offers on lines including Princess, Royal Caribbean, Carnival and Holland America. One of these is a seven-night Inside Passage cruise departing from Seattle on June 21, 2015, on Ruby Princess, starting from $1739.
One last tip for cruising on the ocean: single supplements tend to drop significantly in the shoulder season when companies offer what are called repositioning cruises - essentially moving the ship to cruise in a different part of the world. These cruises are often outside the school holidays and tend to be longer, making them less attractive to families.
There is space for singles on the rivers, too. In 2014 and 2015, Uniworld Boutique River Cruises has waived the single supplement on multiple departure dates on 15 different European itineraries, while there are reduced supplements on other cruises. The 14-day European Serenade along the Danube, Main and Rhine rivers from Vienna to Amsterdam on River Princess and River Duchess departing on July 5 and 18, November 1 and June 25, 2015, is one of these. See the website for specific prices.
Avalon Waterways has a cabin-match program and a single supplement waiver on some 2014 cruises. Examples include a 13-day cruise from Zurich to Amsterdam departing on October 14 and a nine-day Christmastime on the Danube cruise from Vienna to Prague departing on December 3.
Tauck's new Inspiration Class ships Inspire and Savor carry 130 passengers and each has four cabins for solo travellers. And the group has done much to encourage solo travellers with single supplements waived on category one (the smallest class) cabins on all European river cruises this year. There are also savings of up to $1000 on bigger category four and five cabins on selected cruises with single supplement waivers on some 2015 cruises booked through Cruiseabout.
Scenic Cruises has a single balcony stateroom on every ship and regular single supplement waiver specials.
Six AmaWaterways ships cruising in Europe have single-berth cabins and the group, which has chocolate and knitting-themed cruises, announces selected departures with no single supplement about November for the upcoming seasons in Europe and Asia.
APT has single supplement waivers which are usually on sale until December 31 each year.
FACT FILE
cunardline.com.au and 13 24 41.
norwegiancruiseline.com.au.
pocruises.com and 13 24 28.
pearlseascruises.com.
royalcaribbean.com.au and 1800 754 500.
azamaraclubcruises.com and 1800 754 500.
silversea.com.
crystalcruises.com.
hollandamerica.com and 1300 987 322.
fredolsencruises.com.
msc.com.au and 1300 028 582.
companioncruising.com.au and 0468 964 996.
cruiseexpress.com.au and 1300 766 537.
cruiseabout.com.au and 1300 769 228.
uniworldcruises.com.au and 1300 780 231.
avalonwaterways.com.au and 1300 230 234.
tauck.com.au and 1300 732 300.
scenic.com.au and 1300 723 642.
amawaterways.com.
aptouring.com.au and 1300 336 932.