Some island communities are cohesive, others less so, a few not at all. History has something to do with it, but size matters. An island with a very small year-round population can lead to excessive familiarity, which everyone knows can breed contempt. An island community with a large population can easily split into factions on hot button political issues—secession battles come to mind. But on islands that are neither too little nor too big—islands that are just right—community accomplishments keep accruing because their “just right” sense of their island keeps reinforcing itself.

Chebeague Island is one of those communities. I was perusing the Chebeague website the other day, a community effort masterminded by a volunteer, the inimitable Beverly Johnson, who when she is not busy as an island plumber, is at the nexus of the entire central nervous system of the island. When a neuron fires across a synapse anywhere on the island, or within the far reaching networks of “summer natives” that branch out to far-flung northeast, southern or Midwestern locations, Beverly’s fingers twitch and she records the message on www.chebeague.org.

Chebeague’s year-round population is only 375 (check), a goodly number of whom are children and an even healthier number are well advanced in years, but nonetheless, chebeague.org records the daily or weekly activities of a stunning number of Chebeague’s non-profit community institutions. Volunteers sustain the Chebeague Island Community Association, the Chebeague Island Council, the Chebeague Island Community Center, the Chebeague Island Historical Association, the Chebeague Island Library, and Friends of the Library, the Chebeague Parent’s Association, the Chebeague Recreation Center, the Island Commons, Chedemption, the Cumberland Mainland and Islands Trust, the Free Concert Fund and the Chebeague Island Grange. If that were not enough institutions to keep going, there are also a number of summer-oriented non-profits including the Great Chebeague Golf Club, the Great Chebeague Tennis Club and Chebeague Yacht Club. And this does not even count the new town government volunteer posts on the select board, planning board, school board and comprehensive planning committee, or the work for the Chebeague Island Transportation Company. Nor, God bless us, the volunteers for church groups.

It must be something in the water that accounts for this prodigious volunteerism, each of which has its own set of champions on the island. Chebeague’s volunteerism does not even end at the low tide mark of the island. Concern extends throughout Casco Bay with the work of the Casco Bay Island Development Association (C.B.I.D.A.), which is “organized to protect and enhance the livability of the Casco Bay islands and concerned that the setting of precedent can make a threat to any one island a possible danger to all the rest.”

C.B.I.D.A.’s most tireless Chebeague Island volunteer was Jean Dyer, who passed away at age 90 last week, after serving as C.B.I.D.A.’s president for many decades. I first met Jean Dyer, a proverbial little old lady in tennis shoes, back in 1984 at the outset of the Casco Bay island rezoning and development battles when large abandoned military properties on Great Diamond and Long Island were proposed for redevelopment. Jean rallied C.B.I.D.A.’s membership throughout Casco Bay and under her leadership—and with the active support of civic associations on Great Diamond, Long Island and Cliff (and the Island Institute)—put the islands on the political map of Portland, which had previously not paid a lot of attention to the needs of the islanders within its jurisdiction.

The present independent political organization of two of the island communities of Casco Bay—Chebeague and Long—are partly a result of their ethic of active volunteerism as well being just the right size—neither too big nor too little—to maintain themselves as cohesive communities that know what they want and then set their collective minds to accomplishing their goals.

Philip Conkling is president of the Island Institute based in Rockland, Maine.