Visits with their nine grandchildren are always a delight for William and Cosimina Marino of Old Lyme, Connecticut. But at large gatherings it’s often hard to talk to any one grandchild at length, says Mr. Marino.

So it’s no surprise that the Marinos like to travel with their grandchildren—in ones and twos when they can—whether on their boat pulling lobster pots from Long Island Sound or exploring beaches and museums.

It’s no secret to other grandparents that vacation time means quality time. The fact that travel broadens their grandchildren’s experience is not lost on anyone else, either.

“Grandparents want to participate in the cultural enrichment of their grandchild’s life,” says Helena Koenig, founder of Grandtravel, a Chevy Chase, Maryland, travel agency that offers educational trips for grandparents and their grandchildren.

PLANNING TRIPS:

Recognizing consumer demand, a number of travel agencies now specialize in what Dina Long of the American Society of Travel Agents in Alexandria, Virginia, terms intergenerational travel. Agencies such as Grandtravel and Rascals in Paradise in San Francisco, California, offer a range of travel possibilities, from dude ranch stays and African safaris to guided tours of European cities and visits to D day beaches, all tailored to traveling families.

But grandparents can often plan trips just as well themselves, drawing upon their own (often extensive) travel experience or returning to places they took their own children years ago.

The key to successful trips, say travel experts, is education. “Trips and travel in general is about exploring and finding new things. When you share that with your [grandkids] that’s a bonding element,” says Theresa Detchemendy, a co-owner of Rascals in Paradise.

“I think most children are curious and enjoy seeing new places,” says Wallace Sinaiko, a grandfather and retired psychologist from Alexandria, Virginia.

Sinaiko and his wife, Muriel, have taken their granddaughter Rachel on weekend getaways since she was four. Together they’ve hiked Virginia’s Shenandoah National Park, explored underground caverns in West Virginia, visited a Baltimore aquarium, and spent a weekend near Hershey, Pennsylvania, touring pretzel and chocolate factories and riding a steam locomotive through Pennsylvania Dutch country.

The trips are as much fun for them as they are for their granddaughter, says Sinaiko. And the proud grandparents cherish the time spent one-on-one with their granddaughter. “We wouldn’t let anybody else get in the way,” he says.

TRAVEL TIPS:

• Don’t wait until your grandchildren are older to start traveling, says Theresa Detchemendy of Rascals in Paradise. “Get out there and take them places.”
• Grandparents and grandchildren should agree on a destination they want to learn about together.
• Discuss personal routines before the trip. Ask, “Do you sleep with the light on or off? Sleep early or late? Shower in the morning or night?” says Helena Koenig of Grandtravel.