It's crunch time for the cruise industry. Following the Costa Concordia disaster, cruise companies have been aggressively lowering rates and ratcheting up promotions to lure back hesitant passengers.

The two biggest companies -- Royal Caribbean and Carnival Corp., the parent of more than a half-dozen lines, including Costa Cruises -- saw bookings drop by percentages in the midteens in the weeks after the Concordia ran aground off the coast of Isola del Giglio on Jan. 13. Thirty-two people lost their lives or are presumed dead, including Barbara and Gerald Heil of White Bear Lake, Minn.

The accident led the industry to suspend advertising campaigns temporarily and focus on reassuring cruisers about safety instead of sales during its most critical booking time. About a third of all cruises are reserved during the first three months of the year, a time the industry refers to as wave season.

After the Concordia shipwreck, cruise deals on Expedia.com, for example, jumped 60 percent compared with the same time last year. In addition to the reduced deposits and cabin upgrades that Norwegian Cruise Line offered last year during wave season, the company is offering what it calls free balconies -- for example, cabins with balconies for the same price as an ocean-view room.

"This is the perfect time to book this year," said Matthew Lee, vice president for cruises of Travelocity.com, which recently extended its Cruise Super Sale through the end of this month.

Here are some suggestions for nabbing a bargain.

Look for flash sales and stealth discounts. Right now, some of the best deals are being offered in short, last-minute sales bursts or through unadvertised rate cuts. To find them you can check online agencies like Travelocity, the cruise lines' own websites, or CruiseSource.us, which regularly highlights significant deals. Earlier this month, Royal Caribbean listed on its website a five-day Presidents' Day sale. Through May 16, Norway-based Hurtigruten is offering 20 percent off many 12-day sailings to repeat passengers who have sailed for at least three days in the past three years.

And several cruise lines have quietly introduced so-called resident rates, which offer discounts to customers who live in certain states.

"They still want to sell some cabins at full price, so they don't want to make the group of people getting this lower price too big," said Rich Tucker of CruiseDeals.com in Charlotte, N.C. Carnival, for example, is offering residents in 13 states, including Illinois, Ohio and Pennsylvania, $130 off the going rate on a seven-night Caribbean sailing on the Carnival Dream departing March 10 from Port Canaveral, Fla., or $649 a person for an ocean-view room.

You can hunt for online deals on your own by plugging in your state of residence, or you can work with an agent who specializes in cruises to figure out your savings on a particular sailing. One place you can find an agent is CruiseCompete.com, where travelers indicate the cruise they want to take and agents compete to offer them the best deal.

There are plenty of last-minute opportunities for those interested in a quick Caribbean getaway. A seven-night cruise on Carnival Dream, one of the newest Fun Ships, from Port Canaveral to the eastern Caribbean was as low as $449 or $64 a person a night for an inside cabin, including free upgrades, according to Travelocity.

Consider Europe. Promotions are especially plentiful for European cruises, which took a harder hit to bookings than those in North America did, and where high airfares are forcing cruise lines to offer discounts in order to lure American travelers. Among the major cruise lines, prices for European trips are down about 12 percent compared with last year, according to Cayole.com, a cruise shopping site. Azamara Club Cruises is offering $1,000 in airfare credit for two passengers booking ocean-view, veranda or club continent suites on European voyages, and $2,000 in airfare credit to customers booking its top suites.

Europe-bound repositioning cruises -- one-way sailings that cruise lines sell at deep discounts when they relocate ships from, say, the Caribbean in the winter to Europe in the spring -- are particularly good bargains. Norwegian Epic's 11-night trans-Atlantic crossing from Miami to Barcelona on April 14, for example, starts at $699 for a balcony stateroom. That's less than the cheapest one-way flight found on Kayak.com in a recent search.

One place you won't find bargains is on European river cruises, which agents say continue to fill up fast. Avalon Waterways, for example, reports that bookings are much higher than this time last year for its sailings on the Danube, Rhine and other rivers in Europe. Last year at this time Avalon offered travelers $200 off, per person, versus $150 this year.

Don't rule out luxury cruises. Luxury lines continue to slash rates and add perks to get travelers to trade up. "The luxury market is almost in an arms race of who can give more away," said Tucker of Cruisedeals.com. Seabourn, for instance, has introduced a "signature package of benefits," including savings of up to 50 percent, suite upgrades and $1,000 in shipboard credit for premium suites.

And Crystal Cruises said it would stop charging extra for fine wines, premium spirits and gratuities for housekeeping, bar and dining staff beginning next month. The luxury line is also offering tremendous savings through "book now" fares through Tuesday, points out Bob Miller, an owner of Cruise Holidays in Alexandria, Va. For instance, the 10-day cruise from Miami to Lisbon, Portugal, departing March 19, has an ocean-view room starting at $1,360 a person, down from the $4,720 brochure rate.