It isn’t all about the 18-to-49 set

August may be a time for kicking back, but not for two entrepreneurs busy with start-up television networks catering to people who’ve stepped out of life’s fast lane.

A developer of retirement communities is launching a new network on Sept. 5 for that demographic. Initial programming on Retirement Living includes “The Doctor’s Hour,” with geriatric experts taking phone calls from viewers about their aches and pains.

Meanwhile, Plum TV is planning further expansion of a loosely built network of channels that tell vacationers in Nantucket, the Hamptons, Martha’s Vineyard, Vail, Aspen and Telluride where the action is.

What both have in common are driving forces who know more about the niche audiences they’re trying to reach than the television business -- something they both consider an advantage.

“We’re the people who say ‘why not?’ ” said Tom Scott, founder of Plum TV.

Scott and a college buddy one summer sold homemade juice off a boat to vacationers moored in Nantucket’s harbor, building that into the company Nantucket Nectars. They sold a majority stake to Ocean Spray for $70 million in 1997, then realized another windfall -- estimated at $20 million -- when it was swallowed up by Cadbury-Schweppes in 2002.

With time and money on his hands, Scott invested in a Nantucket television station and eventually, in 2002, bought the whole thing.

He quickly recognized the business opportunity in trying to reach people who have a real devotion to their vacation destinations, plus the time to pay attention to what is going on there.

“That’s when I would read three books,” said Scott, 40. “That’s when I would decide to take up yoga. You learn and try new things when you’re on vacation.”

Some of Plum TV’s programs include “Open Exchange,” an interview show with Jonathan Tisch of Loews Corp. talking to other business leaders, and “Beyond Politics,” which talks to politicians in a more relaxed setting than they’re accustomed to.

Yet Plum is less a network than a collection of local affiliates. About 60% of each station’s programming is unique to it, including the flagship morning shows. With studios at local hotspots like the Black Dog in Martha’s Vineyard and off Bridge Street in Vail, these programs deliver news, weather and events listings and are like electronic town squares for their communities.

“Maybe we’ll develop a hit someday,” Scott said. “Everyone likes to develop a hit. The fact is, we are most relevant locally.”

Plum tries to stay relevant in the months when vacationers flee; for example, it presents coverage of high school football on Nantucket. The eventual goal is to establish a Web presence so people can check up on their vacation home communities year-round.

Scott is also anticipating future expansion, predicting Plum will buy an existing station and start another one by the end of the year. He has people with experience in the TV industry working for him, but he sometimes chafes at their rules. For instance, Scott doesn’t like to be hemmed in by schedules, and if a program goes longer or shorter than a typical time slot, he won’t try to stretch or cut.

Just like Scott is learning about the television business, so is John Erickson, founder of Erickson Retirement Communities, 18 separate developments that house about 20,000 people nationwide. Erickson has some media experience; he publishes a magazine aimed at his market.

At its start next month, Erickson’s Retirement Living will be seen from noon to 4 p.m. in more than 9 million Comcast cable homes from Maine to Washington, D.C.

Older Americans watch plenty of TV but most advertisers seek young, impressionable viewers. Most networks put on shows that appeal to them.

Erickson said he had talks with people at Fox about going into business with a network for older viewers. But he said they had more interest than him in airing syndicated reruns, which are generally cheaper than developing new programming.

“People who have looked at it in the [TV] business look at it from the wrong set of eyes,” he said. “They think they could run ‘Golden Girls’ and that’s what they are looking for. It’s demeaning. People are hungry for information and inspiration.”

Retirement Living will air “Amazing Seniors,” about the achievements of people after they’ve retired from traditional jobs. Erickson also wants to set up a “Meet the Press”-style public affairs show, and have programs on personal finance, travel and fitness all directed at the age group. Walter Cronkite has taped some material for him.

Instead of setting up a 24-hour digital channel at first, Erickson is focusing on selling four-hour blocks of programming to some existing channels. About 60% of his targeted audience does not have digital cable or satellite, he said.

“He’s working with Comcast on a how-to segment teaching seniors to make the digital conversion.