For sale: A 3,100-square-foot seasonal cottage with five bedrooms, 3 1/2 baths, and 380 feet of water frontage, abutting 15 acres of conserved forest just a half-mile from Falmouth and 1 1/2 miles from Portland.

The house has three wood-fired fireplaces, septic and sewer service, well water and a gas-fired generator for power.

What the listing doesn’t say – but islanders know – is that it will take more than the $769,000 necessary to buy the house on the northeast corner of Clapboard Island to live there.

Since there’s no ferry access to the island, the buyer must have a boat, or access to one. And typically, an island-home buyer will need the temperament and patience to negotiate the weather and the tides to coordinate trips to and from the mainland. The upside, though, is the solitude and romance of living on an island.

“It’s an extension of a boating lifestyle,” said Paul Clark, owner of Morton Real Estate in Brunswick, who developed homes on Pole Island, a 30-acre spit of land off Harpswell, and maintains a summer home there. “Waking up in the morning, watching the lobster boats and the ducks and geese, and the constantly changing view is amazing. If you love the water and want a little bit of separation from the mainland, an island is no better place.”

That kind of appeal to a very niche market is being watched carefully by the Maine Coast Heritage Trust. Revenue from the sale of the property will help the trust purchase a 17-acre expanse on the northeast part of Clapboard Island. If a buyer isn’t found for the house by Aug. 15, the trust still plans to go ahead with the purchase of the property by tapping a revolving loan fund. The transaction would make way for public access to the island for the first time in more than 100 years.

A REBOUND IN VACATION HOMES

In the trust’s favor is a turning market.

The number of vacation-home sales jumped 29.7 percent in 2013 over the previous year, according to the National Association of Realtors. While still below the market peak in 2006, the average price rose 13 percent over 2012. The same report said there are about 8 million vacation homes nationwide and depicted the typical vacation-home buyer as 43 years old with a household income of $85,600. The vacation home was a median distance of 180 miles from the primary residence, the Realtors group said. About 41 percent of seasonal properties purchased in 2013 were in the South, followed by 28 percent in the West, 18 percent in the Northeast and 14 percent in the Midwest.

Here in Maine, Realtors say that the market for second homes is just starting to come back, driven in large part by low interest rates. Brokers say that island property is often less expensive than comparable properties on the mainland because of the challenge of getting there and maintaining it. And the market has benefited from technology – island homes can now be fueled by solar and wind power, not just propane tanks.

“There’s a certain segment of the market who like the remoteness of an offshore property for seasonal use,” said Rob Williams, of Rob Williams Real Estate on Bailey Island. “It’s a lot quieter. You don’t hear your neighbors driving in in the middle of the night.”

But to be sure, the buyer pool for island real estate is smaller than for a home you can drive right up to. The owner must be committed to the whole enterprise of getting there by his own boat, or willing to pay others to do it for him.

On the southwest portion of Clapboard Island, an eight-bedroom home is on the market for $5.95 million, listed by David Banks, owner of Re/Max by the Bay. The home, put on the market last November, was originally priced at $6.5 million. In addition to tapping traditional marketing channels, the broker is also considering marketing the property to businesses as offices or a corporate retreat, or other uses, said Daniel Cassidy, who is working with Banks to sell the property.

And, they’re targeting people who are not only looking for a place to hang their hat, but maybe just a place to anchor their boat. Not only do they often have the financial means, but for owners of mega yachts, buying an island property as a place to dock their boat can often be less expensive than docking their boat in a marina in the Bahamas, Cassidy said.

REDUX FOR AN ISLAND RETREAT?

“Clapboard has been off the grid since before there was a grid,” said Bill Gillis, great-grandson of Samuel F. Houston, who bought the island from the Brown and Dana families in 1898. Houston, who developed the Chestnut Hill and Germantown neighborhoods of Philadelphia, built an 11-bedroom, one-bathroom, shingle-style summer home on the western part of the island the next year – the $5.95 million home now on the market on the west side of the island. The building materials had been pulled by oxen on sledges across the frozen bay the winter before, said Gillis.

When Gillis started visiting the island in the 1950s, the forests and beaches were the playgrounds for himself and his 18 cousins, who were on summer vacation from Washington, D.C. Electricity came from a gas generator; huge batteries ran the lights; and the garden provided most of the vegetables. Groceries came in from a general store in Falmouth.

In 1975, Gillis’ mother sold the house to friends and built a smaller home at the east end of the island. He and his siblings originally put the smaller house up for sale in September 2011, when the market for second homes was sputtering. There was little interest. By the time potential buyers started to express serious interest in the property, they had already been approached by the land trust about purchasing it, said Gillis, 62, an architectural illustrator based in Louisville, Kentucky.

Gillis said that he is one of a handful of people interested in buying the $769,000 from the trust. He hopes the property will become his so he can continue the family traditions he cherishes with his kids and grandkids.

Two of his kids loved it so much that they moved to Portland as adults, and spend summer weekends on Clapboard.

They are just the sort of potential buyer the island homes should draw, said Mark Small, a Portside Real Estate Group broker who is marketing the Clapboard Island property.

Small said he’s targeted potential buyers locally, as the trust’s fundraising efforts have raised awareness of the beauty and uniqueness of the property .

“We felt strongly that it could be a local person who wants to see this project succeed,” Small said.” It’s such a special spot.”