(MONEY Magazine) – Back when planes had props and cars had fins, a vacationing family snapshot included a breadwinner dad, a homemaker mom and two-plus kids. Fast-forward, however, and half the people in that picture vanish. Today, very often it's just you and your kid vacationing together.

In 1993, says the Washington, D.C. trade group Travel Industry Association of America, a whopping 66 million trips (defined as 100 or more miles from home, one way) involved one or more children but only one adult, up from 46 million in 1988. No wonder: 27% of American children under 18 now live with one parent. And two-income couples, working harder and longer than ever, can't manage to schedule dinners together, much less vacations.

The lone grown-ups on those 66 million trips signal a new breed of family vacationers: kids with a single parent, who might or might not be custodial; one married parent carving out time for children while the spouse stays home; a working mom or dad parlaying a business trip into a holiday; and a grandparent, guardian or other relative treating kids to a junket.

The good news is that the travel industry is finally catching on to the trend. For example, resort chains and cruise lines are paring the 50% to 100% "singles supplement" charge that penalizes solo travelers, while tour operators and outfitters are busy designing packages to attract these new voyagers.

"Single parents on vacation want to socialize with other single parents, who understand what it's like if your kid's got a fever," explains Bill Scalzitti, who organizes single-parent weekends at the Concord Hotel in New York's Catskill mountains for Parentguide, a monthly newspaper ($17 per year; 212-213-8840). One weekend last January attracted 80 adults and 93 kids, ages two to 16, for skiing, ice skating and tobogganing (cost for two nights for one adult and one child: $398, which includes room, meals, activities, taxes and tips).

With the '95 holiday season approaching, we canvassed travel-biz agents, packagers and consultants to uncover the latest reliable sources and tips for vacations geared to one traveler with kids in tow. Here's where to go and what to do:

FRIENDLY SEAS. A few years back, the $8 billion cruise industry discovered that if it added shipboard kids' menus, activities, day care, game rooms and special discounts, families would come cruising. Now some lines have expanded to include single-parent alternatives. One popular package is offered by Premier Cruise Lines (800-327-9766) on its two Big Red Boats, holding 1,550 and 1,800 passengers. The three- or four-night cruises depart from Port Canaveral, Fla., stopping at Port Lucaya and Nassau, and including three or four nights in Orlando to visit the Magic Kingdom and Universal Studios ($1,436 to $1,799 for one adult plus $529 to $559 for each child ages two through 11, except holiday weekends such as Independence Day and Christmas). Rates are only 25% more than per-person double occupancy.

AFFORDABLE SAND CASTLES. All-inclusive resorts, where the package price pays for all services, activities, room, meals and sometimes air fare, make it easy to say yes when the kids want to try everything. Plus, the range of sports and recreation options allows single parents to juggle kid time with kickback leisure of their own. After years of specializing in high value for singles, Club Med (800-258-2633) now hosts 70,000 children worldwide in more than 100 of its 114 resorts. Prices for the Kids Free plan at Sandpiper in Florida, St. Lucia and Punta Cana in the Caribbean, Eleuthera in the Bahamas and Ixtapa in Mexico range from $749 to $980 a week for one child under five with one adult, including lodging, meals and most activities (but not air fare). The rates are not available for holidays. Anyone over 55--think doting grandparent--gets an additional $140 off at Sandpiper, Eleuthera or Ixtapa.

If you're the flexible type, sign on for Club Med's Family Escape plan: You get the same meals, accommodations and activities plus round-trip fare from New York for only $1,499 for one adult and one child age two to 11, or $2,249 with two kids in that age group. But Club Med picks your destination depending on availability, typically in the Caribbean or Mexico. And you don't find out where you're going until two weeks before departure.

PERKS FOR FLYING SOLO. From June 1 to Aug. 31, the 507-room Holiday Inn Sun Spree Resort in Lake Buena Vista, Fla. (800-366-6299) is offering a four-day, three-night combo for only $343 for a parent and up to four children, including meals, tickets to nearby Disney World, unlimited use of an on-site 9 a.m.-to-midnight day-care center and evening magic shows and karaoke. Although you must all share one room, you get two queen-size beds, cribs and sleeping bags; a rollaway bed is $8 extra per night. The 670-room Holiday Inn Main Gate East in Kissimmee (800-366-5437), three miles east of the Magic Kingdom, features similar amenities for three nights at $290 for one adult and up to three children.

Prefer another frontier? A weary parent can relax in a whirlpool beneath a waterfall at the 295-room Hyatt Regency Beaver Creek in Colorado (303-949-1234) while kids pan for gold and hear fireside stories at Camp Hyatt. The resort's new single-parent package gives one adult and one child a room for two nights ($280 to $450, depending on the season), a cookies-and-milk welcome and one room-service breakfast, plus three hours at Camp Hyatt for the child and two daylong health club passes for the adult.

BIKES, BOATS AND DOGSLEDS. Active vacations, like mountain climbing, bike trips or sea kayaking, are popular with single parents whose kids are older and more independent. "Adventure trips attract a mixture of family and nonfamily travelers, so a single parent is not an apple among plums--just an apple in a fruit bowl," says Dorothy Jordon, editor and publisher of Family Travel Times, a newsletter published four times a year ($40 annually; 212-206-0688). Perhaps most important, "Active trips are great bonding experiences," says Michael Spring, publisher of Frommer's Travel Guides. He took his two sons, now 27 and 29, dogsledding in Alaska, hiking in the Arctic Circle and llama trekking in Montana when they were teenagers.

If you're itching for the exotic, consider Escapes Unlimited, an Orange, Calif. adventure-travel firm (800-243-7227). Last year, the packager introduced one- and two-week trips for groups of as many as 20 single adults and children over age seven to such places as Bali, Costa Rica and the Gal‡pagos Islands (cost for a typical Bali trip: $2,299 for adults and $1,699 for each child under 12, including round-trip air fare from Los Angeles, hotels, some meals and all sightseeing).

You can avoid the singles' supplement entirely if you're willing to share rooms with another (same sex) single parent and his or her kid. Most adventure packagers will arrange such matches if you sign on at least 60 days before departure.

MIX FAMILY WITH BUSINESS. By extending her business trips over a weekend and thus rating the Saturday-night-stay discount fares, Karen Shanor, a Washington, D.C. clinical psychologist and single parent, finds she can often bring along her son Daniel, 11, at no extra cost. A growing number of all-suite hotels, offering two-room accommodations at no more charge than local hotel rooms, also boost her budget. At the 109-hotel Embassy Suites (800-362-1779), for instance, the largest all-suite chain, an average $97 a night gets you a bedroom with a double bed and a living-room area with a sleeper sofa, rollaway bed (or crib, if needed), plus free breakfasts. Nearly a third of Embassy Suites hotels have on-site, supervised children's activities for about $3 per hour from 9 a.m. to 5 p.m.; some offer nighttime babysitters for about $3 an hour.

Of course, older children may not relish being dropped off at a day-care center. Shanor recently gave her son a choice between watching TV and accompanying her to a lecture on the brain and consciousness. "He came," she recalls, "and took notes."

TIPS FROM SINGLE-PARENT ROAD WARRIORS

When considering any trip, ask the tour operator to describe your fellow travelers, including the adults' marital status and the children's ages, to make sure you'll be comfortable and compatible.

Travel costs for a second child are often so minimal that it may pay to invite one of your kid's friends. Then your child gets a built-in playmate, and you get more time off.

If you plan to travel with another single parent and child, make sure the youngsters also like the idea.

Headed overseas? Ask the embassy or consulate of the destination country whether you need notarized authorization from the child's stay-at-home parent to accompany the child, even if you're the custodial parent. Such permission is required in a few countries, including Australia, Brazil and Mexico.