For $415,000, you get the key to a Vineyard oasis

CHILMARK -- There's no towel service, no cabana boy, and you'll have to bring your own sunscreen. But for $415,000, you, too, can spread out on what some say is one of the most exclusive beaches around.

The little-known gated beaches on Martha's Vineyard, with names like Quansoo and Black Point, have long been sealed off, provinces of a select number of members who own keys to the gates. Lately, as more people seek the privacy and bragging rights of owning their own piece of beach, prices have soared. Once selling for a few thousand dollars each, shares now routinely fetch hundreds of thousands. Some have sold for quadruple the prices they brought just a few years ago.

What do you get for your money? At Quansoo, it is a deed for one seventy-seventh of a mile-long stretch of white sand and dune grass and a high-tech key. Plus, there's a property tax bill of $539 and nominal annual association dues of about $150.

Shares once tended to stay in families. But now demand is driving faster turnover than some members have ever seen. In the past five years, at least 56 shares, known locally as ''beach keys," have changed hands, with at least 15 bringing more than $200,000, according to property records. One sold for $375,000. A local realtor said a half dozen are on the market now, with prices up to $415,000.

''When people are seeking exclusivity, it proves they'll pay just about anything," said John Alley, former co-owner of Alley's General Store and a Vineyard resident.

It is one of the more vivid examples of over-the-top extravagance that has taken over this one-time backwater farming community, where the average price for a house has touched $800,000 and where some year-round residents contend the island has become a playground for the nouveau riche.

The beach-key concept appears to be unique to Martha's Vineyard. The town of Chilmark has at least four gated beach associations: Quansoo, Black Point, Stonewall, and Hancock. If there are others, on Nantucket or elsewhere, no one's talking about them.

The existence of the Vineyard beaches is a secret almost as heavily guarded as the beaches themselves, where summertime guards hired by the beach associations often check the license plates and keys of every beachgoer.

The past president of the Martha's Vineyard Chamber of Commerce heard about the beaches only in recent months, despite living and working on Martha's Vineyard for 17 years. ''It's one of the untold secrets of the island," said Linda Malcouronne, who thought rumors about them were just another island legend. She still does not know where the beaches are or anyone who owns a key.

There's a good reason for that, it turns out. ''We're not supposed to tell people where it is, unless they're family members or guests," said one Quansoo key owner, who spoke on condition of anonymity because she feared retribution from other beach-key owners.

On a recent visit, Quansoo and Black Point seemed like many other beaches on the East Coast. Each is about a mile from one of Chilmark's main drags, down a winding, sandy road best negotiated with a four-wheel-drive vehicle. Each has a gate across the road. Quansoo's is galvanized steel; Black Point's, next door, is wooden with heavy-duty padlocks.

At entrances to both, extensive regulations are posted, including how many guests are allowed -- no more than 20 without permission -- and rules governing use of the keys. ''Do not duplicate keys or leave keys at gate," Black Point regulations say.

At the shore, dunes dappled by brush and scrub overlook a white, sandy beach where wind-whipped waves roll ashore.

''I come here to be alone," Michael Holtham, 21, said last week, standing on Quansoo Beach looking out at the sea. His family secured a key when they bought property about a mile from the beach 30 years ago. Then, the price of a key was $5,000. ''You can't own beach anywhere else, really," Holtham said.

The gated-beach concept on the Vineyard dates back to the 1950s, when families who owned swaths of land began subdividing the land into lots and selling them. At the same time, stretches of beach were organized into associations. It was part forethought -- to avoid development that would lead to the ''ticky-tacky" feel of the Jersey Shore, according to one family descendant, Susan B. Whiting -- and part incentive for prospective buyers. Shares initially came with lots that were not on the water.

Quansoo is valued by town assessors at $21.2 million, or about $275,000 for each shareholder. Officials said that figure is well below market prices and will probably go up significantly at the next valuation. That shares of private beaches are going for such high prices has only aggravated fears among longtime residents that rich newcomers are spoiling old ways. Whiting recalled a Vineyard era when wives lived on the island full time in the summer while their husbands visited on weekends.

''Now these people come and build 16-bedroom, five-bath houses; they stay two weeks a year, and they don't give a tinker's damn about the community," said Whiting, whose family cofounded the Quansoo Beach Association with land that Whiting said had been handed down in her family since the 1600s.

Holtham said he begged his mother not to sell the family's Quansoo key. She sold the family house, but he persuaded her to keep the key. ''It's just a good place to find serenity," Holtham said, gazing at the surf. ''Close your eyes, and you could be anywhere."

Donovan Slack can be reached at dslack@globe.com.