There'll probably be plenty of other kids to hang out with; more children and teens sail on Carnival ships than on any other cruise line. The ship's Club 02 teen program hosts nightly dances as well as waterslide races, scavenger hunts, and other games. Because teens tend to make friends and form groups quickly, we urge the girls to join the group soon after boarding. Many teen activities last until the wee hours of the night, so the mothers will want to discuss curfews beforehand.

Cruises are cashless environments: Everything passengers buy is charged directly to their accounts by way of a stateroom key card. The moms aren't sure if they should allow Nicole and Leticia charging privileges. If they do, we strongly advise ground rules, perhaps telling the girls they're limited to a certain amount each day. Karen and Wendy can periodically ask for a printout of their accounts.

The group at Stingray City (Vanessa Rogers) [enlarge photo] FEBRUARY 2007 ISSUE • Table of Contents • Secret Hotels of the Riviera Maya • James Turrell: Sky High • Dubai: Just Add Money • Eat Like a Local: Melbourne • Five Hotels: What 99 Pounds Buys in London • Road Trip: Hawaii • 40 Best Vacations

Ports and excursions

Exploring independently often costs less than organized ship excursions. In Grand Cayman, the foursome can take a walk to George Town for upscale boutiques. In Cozumel, there are good jewelry stores in a huge building right by the pier. Haggling is a must.

As for organized day trips, a tubing adventure through caves in Belize costs $79 through Carnival. There's no requirement to book excursions through the ship, though. Belize Cruise Shore Excursions, an independent tour group, sells a slightly shorter version for $60 (belizecruiseexcursions.com). "That leaves us time for shopping," says Wendy.

Of the ship's excursions, a few stand out as likely favorites. The Stingray City trip in Grand Cayman ($74) includes a tour of the island and the chance to get in the water with actual rays. In Mexico, they might prefer the Chacchoben Mayan Ruins program ($69), which visits impressive pyramids in a secluded jungle, to the Tulúm trip ($79). The group is most fascinated by an all-day, Mayan Jungle Explorer tour ($109) with biking, snorkeling, and zip lining. "What a day that'll be!" exclaims Wendy. Bon voyage!

Just some of the answers that experts have given during weekly chats at our website, BudgetTravelOnline.com . . .

Costa Rica: "Forget the malaria concerns. You have a much better chance of being eaten by a polar bear." -- Rob Hodel, cofounder of Tico Travel

Mount Kilimanjaro: "Find yourself a lunar calendar and plan to hit the summit on or around full moon. You'll not regret it." -- 2Afrika president Kenneth R. Hieber

Las Vegas: "Pirates can serve as the ring bearers and even give the bride away." -- John Bigley and Paris Permenter, authors of The Destination Wedding Workbook, on getting married at Treasure Island

Cell Phones: "Your standard Verizon phone is a paperweight overseas." -- Ken Grunski, CEO of Telestial, on the limitations of some U.S.-based cell phones in Ireland

Buy any good souvenirs?