NEW YORK (The Wall Street Journal) ? Helen Tepper and her husband, Jerry, booked a cruise to the Indian Ocean so they could mingle with other passengers, relax on the deck and take part in a slew of onboard activities.

But once at sea, the plan veered off course ? with the Teppers missing an onboard art auction, power-walking classes at the health club and a tiki party on the Lido Deck.

The problem: Their 30-day cruise?s itinerary had them spending much of their time on land in 13 ports from Bangkok to Cape Town, and not as much time lounging on deck. ?We were exhausted,? says the 62-year-old Mrs. Tepper. This season, cruise ships are doing less cruising and more sitting, as big operators pitch itineraries with multiple-day, onshore excursions.

Silversea now offers overnight stays in Moscow during its Baltic Sea itinerary ? including a ride on a MiG fighter jet and a visit to the State Circus ? nearly doubling the time cruisers spend in the Russian capital.

The ship on Seabourn?s Red Sea and Africa cruise will spend twice as much time this year docked in Cairo, letting some passengers take a six-hour trip for dinner at the Nile-side home of the widow of the late Egyptian president Anwar Sadat.

Crystal Cruises just introduced its longest side trip yet, a five-night safari through Kenya and Tanzania ? two days longer than its previous safaris and one-third of the entire cruise length. ?Sure it?s exhausting, but it?s like working out,? says Crystal President John Stoll. ?You?re sore, but sore in a good way.?

Cruise companies say they?re offering ambitious shore excursions in part to attract younger and more-active travelers.

The average age of cruise-goers is 50 years old, down from 60 a decade ago, according to estimates by the Cruise Lines International Association, an industry trade group.

?Ten years ago we might have had a motor coach to drive guests through the rain forest,? says Deborah Natansohn, president of Seabourn Cruises. ?Now they want to swing from the treetops.?

But optional field trips are also a way for operators to squeeze extra cash out of passengers. Cruise-occupancy levels stand at 105 percent, the cruise-lines association says. (It?s higher than 100 percent because families of three, for example, can squeeze into double rooms.)

But to keep occupancy so strong, operators have offered rate cuts, with many charging less now than they did before Sept. 11.

The average price for a Carnival Corp. cruise ? the industry giant owns 12 lines, including Holland America, Cunard, Seabourn and Carnival ? is $172 a day per person, up from $153 in 2002, but down from $193 in 2001. To help make up some of the difference, operators are charging extra for everything from cooking classes to spa treatments ? with Seabourn?s Cairo dinner with Gihan Sadat, for example, running $9,000.

This growing revenue stream now accounts for more than 25 percent of total revenue, cruise lines and industry analysts say.

Moreover, limiting the time passengers spend onboard actually induces them to spend even more, cruise operators say, because they feel pressure to get the most out of their time.

But there are drawbacks to carving out extra hours for overland jaunts. For starters, it asks cruisers to pay twice ? once for the package that includes shipboard room and meals, then an extra fee for overland transport, food and hotel.

Plus, operators risk alienating their old-guard customers. Passengers who have taken more than five cruises account for 46 percent of the overall business, according to CLIA, and for this segment, onboard activities are a big draw: 36 percent of these repeat cruisers say they like to attend ship dances, for example, compared with 26 percent of first-time cruisers.

Ellis Olczak doesn?t sign up for a boat trip so she can spend all her time tied up at the port. The 81-year-old in Temperance, Michigan, has 31 cruises under her belt, and this fall she?s planning to take Holland America?s M/S Statendam on a two-month tour of Asia.

?All 62 days I?ll be in the same room ? after I unpack I?m not going anywhere,? says Ms Olczak. But she?s worried she?ll spend too much time docked in Shanghai while her friends go on a three-night inland excursion to see the terra-cotta warriors in Xian, China. ?If you want to really get to know a country, why not just fly there??

Not long ago, of course, cruise ships generally were seen as floating resorts where meals and entertainment were included, views were always shifting and shore visits meant little more than a bus tour around town while the ship took on fuel and supplies.

Land options started becoming more elaborate about a decade ago, as operators made a bigger push for reluctant cruisers who didn?t want to spend a whole vacation stuck onboard.

Now, cruise lines say longer land excursions help them compete with tour operators ? especially in spots such as Europe, where US customers who book for their trip in advance can pay for side excursions in US dollars, which may make the trip cheaper than paying in stronger local currencies.

Crystal Cruises says its move to more port-intensive itineraries is a response to surveys it conducted onboard last year, in which most customers asked for side trips. (The company would not disclose the survey?s specifics.)

This summer, the company added a two-night tour to Krakow from the port of Gdansk, Poland, with a side trip to Auschwitz, and next year, the average 12-day Crystal cruise will spend two or three days at sea, down from five days in years past. To make sure its more leisure-minded passengers aren?t steered wrong, the operator also has added icons to its brochure to indicate the level of intensity of each excursion.

Chris Krondon had never even considered taking a cruise until a friend recommended it as a good way to meet people, and see more than one destination.

The 31-year-old construction manager from Tampa, Florida, decided to forgo his annual skiing trip this year and has booked a seven-day Caribbean cruise instead. His off-ship agenda? ?It?s either a scuba diving trip in Belize or an 11-hour trip to Cozumel,? he says. ?I?m trying to pick the most fun one.?

Cruiser Jan Erickson has noticed an onboard rift between ship people and land people. While the 57-year-old from Bothell, Washington, says she always gets off for a stroll at port, she prefers to spend most of her time on the ship, working on her needlepoint or attending guest lectures with cruisemates.

People who spend all their time on land interrupt the ?community and family feeling onboard? says Ms. Erickson, who recently returned from a Radisson Seven Seas around-the-world cruise. ?You have to work very hard to draw them out.?

Cruise line Cunard, for its part, says it?s trying to strike a balance between the two.

This year, the company added three new overland tours, which the company defines as a trip beginning in one port and rejoining the ship in another ? so sea lovers can stay onboard, for example, while adventurers traipse through Laos for five days.

?Some passengers ask us why they have to build ruins so far from the ship, but in general we?re seeing great interest and an increase in spending,? says Bruce Krumrine, who designs Cunard?s land tours.

He says ten percent to 15 percent of passengers sign up for overnight trips, while 60 percent to 70 percent stick to day trips.

Though cruise lines won?t disclose their margins on shore excursions, the markups range from 20 percent to 100 percent, according to estimates by industry analysts, local tour operators and travel agents.

Cruise lines including Carnival, Cunard, Seabourn and Princess don?t dispute these margins but say side trips cost a lot to develop, and point out that operators have to pay extra for attractions to open on holidays or for buses that aren?t filled to capacity.