The Martha’s Vineyard Commission voted without dissent last night to designate the waters around the Vineyard as a district of critical planning concern, cementing a yearlong moratorium on building wind farms in nearshore waters while rules are developed.

But a parallel plan to nominate an Islandwide DCPC on land for wind power developments was successfully resisted by the Edgartown selectmen, who are intent on building a 363-foot tall wind turbine at the town wastewater plant.

The commission last night agreed to Edgartown’s request that it be excluded from a nomination for a district of critical planning concern, which was originally proposed to cover all the Island towns.

Once designated, a DCPC would allow a year’s hiatus in large turbine construction all across the Island while rules for wind power developments are created.

The commission did it reluctantly. But as longtime commissioner Linda Sibley of West Tisbury put it, any attempt to coerce Edgartown into taking part would have been “political poison.”

Although the commission’s enabling legislation gives it clear power to impose a DCPC which includes Edgartown, she said: “We have not in 35 years imposed a DCPC on a town that didn’t want it”, and she “sure as heck” was not prepared to do it now.

So five of the six Island towns now are under a short-term moratorium relating to structures more than 150 feet high, while Edgartown remains free to pursue its plans for a structure more than twice as high. A vote to designate the DCPC will be scheduled within 30 days.

No Edgartown selectmen attended last night’s meeting, an action that was roundly condemned by several members of the commission.

Commissioner Ned Orleans of Vineyard Haven described a letter from the selectmen opposing the town’s inclusion in an Islandwide DCPC as “one of the snottiest” he’d ever read.

Dated Oct. 13, the letter accuses members of the commission of using the DCPC process to “short circuit” the town’s own regulatory process in pursuit of other agendas.

“We are well aware of the opinions of some of the individual commission members that would like to see all of Martha’s Vineyard under a DCPC in order to implement the Island Plan and we are in disagreement with that opinion,” the letter said.

“It is unfortunate that the Island’s uniting on issues surrounding the ocean management plan is being lost in an attempt to tack on DCPCs that have no bearing on the ocean management plan. We would hope that the commission will refocus on the issue that brought us together in the first place . . . .”

Other commission members also were sharply critical of the three Edgartown selectmen — Arthur Smadbeck, Michael Donaroma and Margaret Serpa — going so far as to suggest they did not represent the views of their townspeople.

Commissioner Holly Stephenson of Vineyard Haven asked whether the commission could impose an Islandwide DCPC, with an “opt-out” provision that could be debated at town meeting.

That idea went nowhere, but Mrs. Sibley suggested a group of Edgartown residents could petition to have the town included in the DCPC.

Edgartown already has in place regulations for wind turbine developments, but commissioner Douglas Sederholm of Chilmark said he had read them and found them “pretty darned weak, frankly.”

Commissioner John Breckenridge of Oak Bluffs agreed, saying they do not address issues such as scenic and cultural values.

Mr. Sederholm said he was concerned that Edgartown sought “to exempt itself from a process sought by all other towns.”

A big windmill, he said, could have an impact on the entire Island; his concern was echoed by others. Mrs. Stephenson noted a 363-foot tall structure was as high as a 40-story building, and would be visible all over the Island.

There was more discussion about whether the MVC could intervene by other means, such as a referral of the turbine project as a development of regional impact.

But in the end the nomination was amended to exclude Edgartown, although Mrs. Stephenson abstained, citing a “certain lack of integrity” in imposing a moratorium in all other towns and leaving Edgartown out.

Before voting, the commission willingly made an exception for another large, 218-foot wind turbine being built at the West Tisbury School.

The DCPC nomination originally proposed a height limit of 220 feet, which would have conveniently accommodated the school turbine. But after much talk the limit for that project was reduced to 150 feet.

Chilmark selectman J.B. Riggs Parker played a prominent role in the discussion, saying such tall structures of any kind were “counter to all the Island has stood for,” and claiming the Vineyard is “about to be assaulted by all kinds of windmills.”

When the height limit was reduced, an exception was made for turbines on school properties.

The discussion of land-based turbines followed a public hearing on a proposed DCPC applying to offshore wind generation, which is the commission’s core concern, because that is where the greatest prospect of large scale wind generation lies.

The DCPC on water was nominated last month; last night’s vote was to formally designate it, extending the moratorium for one year while towns develop regulations, in conformity with guidelines set by the MVC, for the development of wind power in waters up to three miles offshore.

About a dozen people spoke, most in opposition to the idea of turbines in Island waters.

On the other side, Chris Fried, a strong advocate of alternative energy who has attended most of the public gatherings on the subject, said he was upset by the amount of time spent “wiggling about” looking for reasons to oppose wind power, and lack of focus on the urgency of addressing climate change.

The commission got into a debate about whether the structure height proposed for the DCPC — 220 feet above sea level — is adequate or should be reduced. There was no consensus and they decided to revisit the matter later.

But the matter of a DCPC over waters around the Vineyard and Elizabeth islands was never in doubt. The vote was 14-0 in favor.

In another related matter, the commission voted to join the Cape Cod Commission as a friend of the court in legal action now under way between that commission and the state Energy Facilities Siting Board.

Because the case centers on who has jurisdiction over large-scale energy projects, it could be relevant to the Vineyard commission in the future.

As things currently stand, the Oceans Act limits the Island’s role in decision making on energy developments over water. Island towns, the Dukes County Commission, MVC and Wampanoag tribe are mounting a rear guard action to try to change that.

A delegation from the Vineyard will meet with Ian Bowles, the Secretary for Energy and Environmental Affairs, in Boston next Friday, to press the case.