From 1913, we have a story of what might have been on Chappaquiddick. And from Thanksgiving weekend, we have a story of what might have been lost in the century since then.

A hundred years ago this May, the State Street Trust Co. of Boston began to promote a subdivision of 775 lots measuring 10,000 square feet each on the oceanfront plains of Wasque Point. Ultimately the development, called Chappaquiddick-By-The-Sea (“Every breeze a sea breeze”), was unsuccessful; only a handful of lots were sold, and only three cottages ever built.

Which, for prospective landowners, cottage builders and descendants turns out to have been a very good thing. This stretch of the Vineyard and Chappy shoreline erodes more spectacularly and permanently than just about any other along the New England coastline. Though the developers probably didn’t know it, what might have been built at Wasque was not destined to last.

A main reason, coastal experts say, has to do with the periodic opening of a nearby barrier beach to the sea — a cataclysmic event that severs Chappaquiddick from the rest of the Vineyard and last occurred during the Patriots’ Day storm of early April 2007.

Old map shows 775-lot subdivision, which is today Wasque Reservation. — Courtesy Woody Filley

After Norton Point opens, the new inlet prevents sediment from reaching the Chappy coastline from the west. The beach defending the Chappaquiddick shore from the Atlantic withers away, ocean waves attack the bluffs that rise behind the beach, and the whole southern shore of Chappaquiddick begins to fall away at breathtaking rates — sometimes as much as 30 feet overnight during a vigorous storm.

This process can go on for years at a time, as Vineyarders have seen recently, and it doesn’t end until the opening migrates to the elbow of Wasque Point and closes. The shoreline then stabilizes until another tempest re-opens the beach and the cycle begins anew.

Over Thanksgiving weekend, Woody Filley, a Chappy resident and director of information technology at the Martha’s Vineyard Regional High School, e-mailed a copy of the ancient Chappaquiddick-By-The-Sea development plan to his friends.

Of course the subdivision was never built — most of the land was placed in conservation in the late 1960s and is today Wasque Reservation, owned by The Trustees of Reservations. But Mr. Filley wondered how much of the subdivision would have been lost to erosion over the course of five separate openings since 1913. To find out, Dana Gaines, an artist who owns a home on Chappaquiddick, did some jiggering and lay the latest Google map (from March 2012) over the failed development plan.

The answer: The ocean would have claimed somewhere between a quarter and a third of the little Chappy Levittown, chewing up as many as 250 lots. But that’s as of 21 months ago. Thanks to measurements taken regularly by Bob Gilkes of Edgartown and Mr. Filley and Skip Bettencourt of Chappaquiddick since the most recent opening occurred, Mr. Gaines estimates that another 24 lots at least would have been lost to the Atlantic just since then.

Forget “Every breeze a sea breeze.” The promotional line in the brochure might more accurately have read: “Every lot a waterfront lot — and sooner rather than later.”