Leading cruise lines have fought off recession by slashing their prices to new lows, but some passengers could be in line for a shock when they get on board, according to a leading cruise expert.
Douglas Ward, author of the Berlitz Complete Guide To Cruising And Cruise Ships 2014, says: "Although more than 22 million people worldwide will take a cruise in 2013, cruise companies are finding the economic waters unpleasantly choppy, particularly the sudden dive in bookings following the Costa Concordia tragedy.
"When you see prices falling towards STG60 ($A92) per day, you have to wonder how cruise lines balance that with the cost of food, the wages bill, plus the rising fuel costs - and still make profits. I would struggle to find a hotel room on land at those prices."
The new edition of the Berlitz Guide says many cruise lines maintain impressively high standards: it names Cunard's Queen Mary 2 (Grill Class) and the Celebrity ships Equinox and Solstice as the top large ships, with Crystal and Seabourn cruise ships and the Europa, operated by Hapag-Lloyd Cruises, as best among the smaller categories.
The Guide points out that cruise lines, to keep their heads above water, have switched ships away from low-profit regions such as the Caribbean and Alaska to Europe, South-East Asia and Australasia.
However, Ward believes many cruise lines can only afford to offer strikingly low fares by boosting revenues in subtle ways elsewhere.
He identifies the 'six big cruise line rip-offs' as:
Currency conversion: Thanks to credit cards, cruise lines take total control of your onboard account and they might switch your bill to US dollars on dates in the month when conversion charges work in their favour.
Extra gratuities: An additional gratuity line is often added to signable receipts on things like spa treatments and extra-cost coffees.
Transfer buses: Used to be largely free. Now even airport transfers might cost extra in cities like Athens, Barcelona and Civitavecchia in Rome.
Charging for mineral water: Often per bottle on shore excursions, perhaps even with a gratuity on top.
Navigational bridge tours: One cruise line charges passengers $150 to be entered into a raffle to win one of a handful of tickets to see the bridge.
Bingo cards: Prices are 'rising dramatically', with one line - NCL - charging $40 for four cards.
Numerous cost-cutting ploys, says Ward, include the reduction of food portions, making the free coffee a little weaker, cutting the variety of green vegetables and removing in-cabin toiletries.
The removal of trays at self-service buffets means some passengers can't eat as much, and ships often cut speeds between ports to save on fuel.
Some ships charge for postcards which used to be free, replace live flowers with silk flowers, and remove free writing paper and accessories.
Ward says: "Basic prices for cruises have never been better value, thanks in part to the economic downturn that has forced cruise lines to offer more booking incentives, such as onboard credit and cabin upgrades. But cruise companies must push hard to boost onboard revenue from extras.
"However, my fear is that this focus on low prices may not be sustainable in the longer term: it may make it more difficult for small cruise lines to compete with the big boys, yet many passengers love the small, older ships of the small companies.
"As prices are forced down, there are bound to be economies on some ships charging the lowest prices: there is less to spend on food, and perhaps the freshness of vegetables and fruit suffers. Passengers on restricted diets might not always have the choice of diet they have come to expect."
At the moment, Ward says, there is a strange equilibrium in the industry: while the biggest ships belong to lines like Carnival and RCCL, which can slash operating costs by central purchasing, the smaller cruise lines tend to operate much older ships which don't require large loans. So they spend much less on servicing debt repayments.
Canny cruisers, says the Guide, note headline prices in newspapers and TV adverts. But they often find the best value in other ways.
For best prices, and to get the cabin you want, it usually makes sense to book early. Late bookers often get a good price, but they might also get a 'tiny cupboard above the galley' as a cabin.
Choose an older ship, because the newest ships command a premium.
Ward says: "Remember the old maxim: Pay cheap, get cheap. Passengers should have to decide a strategy: either go for lowest possible prices, or pay extra for a bit more choice, comfort and style."
If you are on a tight budget, the Berlitz Guide advises, it makes sense to book an interior cabin on one of the better ships, rather than an outside cabin on a less fancy ship. This usually buys better food and entertainment for the same money.
Where growing families are involved, it might also make sense to book a drinks-inclusive package from the start, to keep onboard spending down.
The new Berlitz Guide to Cruising and Cruise Ships - the 28th edition of the publication - rates 11 brand new ships for 2013, and previews seven new ones, which will be launching soon.
One sector which is expanding particularly rapidly, the guide says, is expedition ships on voyages of discovery to far flung corners of the globe such as the Antarctic, where nobody is too worried about getting a tan.