What Nobody Tells You About the Other Casco Bay Islands

Population Counts That Do Not Agree With Each Other

Start with Great Diamond Island. Wikipedia's most recent independently confirmed figure is 77 year-round residents, drawn from the 2000 Census. A commercial demographics aggregator, Point2Homes, shows a very different current snapshot: 12 residents across just 6 occupied households, with a median age of 71.5. Those two numbers are not close, and this page is not going to pick one and call it settled -- the gap may reflect a narrower tract boundary, a different survey year, or something else about Point2Homes' methodology that was not independently confirmed. What can be said honestly is that Great Diamond's year-round population is small, likely well under 100, and that a prospective buyer should treat any single figure they encounter elsewhere as provisional until checked against a primary source.

Little Diamond Island's numbers are even smaller and even stranger. The 2000 Census put year-round population at 5 residents, a figure Wikipedia explicitly attributes to the island's water supply being shut off in winter -- there is a real, documented reason so few people live there year-round, not just a vague sense of remoteness. A more recent Point2Homes snapshot shows an even thinner picture still: 2 residents, 1 occupied household out of only 3 total housing units on the entire island, a 66.7% vacancy rate, and a median construction year of 1938. Whether the true current number is closer to 5 or closer to 2, Little Diamond functions as a tiny, largely vacant, privately owned seasonal-cottage enclave, not a year-round neighborhood -- and its winter water shutoff is the specific, documented reason why.

The "Smallest Island" Claim That Does Not Quite Add Up

Casco Bay Lines' own page for Cliff Island describes it as "the smallest year-round inhabited island in Casco Bay." Cliff Island's own population is genuinely small -- roughly 60 people as of the 2000 Census, swelling to about 200 in summer -- but Little Diamond Island's figures above (5 residents at the 2000 Census, and as few as 2 in a more recent snapshot) are smaller still. This page is not going to silently resolve that contradiction by picking a side. The most plausible explanation is that Little Diamond functions as a private, largely seasonal retreat rather than an organized year-round community, while Cliff Island has a genuine, organized civic and school life -- a one-room schoolhouse, a library over a century old, a historical society, and an all-volunteer community organization running an active event calendar. Casco Bay Lines' claim may be implicitly measuring "smallest inhabited community" rather than "smallest population count," but that distinction was not stated by the source itself. Treat the claim as a piece of marketing language sitting in real tension with the population data, not as a settled fact.

Land Area: A Genuine Gap, Not a Rounding Error

For Long Island and Chebeague Island, land area is well documented: Long Island's incorporated town covers 33.52 square miles on paper, but 32.10 of that is water -- actual land area is just 1.42 square miles. Chebeague's total area is 24.56 square miles, of which 3.56 is land. For Great Diamond Island and Little Diamond Island, no specific land-area figure was independently confirmed in this research pass at all. That is a real gap, not an oversight in this page's writing -- if a specific acreage number for either island shows up in a listing or a third-party site, it has not been verified here and should be checked against a primary source (a county GIS parcel record or the City of Portland's own assessor data) before being relied on.

Real Estate Prices You Should Not Trust Yet

Zillow maintains a confirmed typical-home-value (ZHVI) figure for two of these five islands: Chebeague Island at $666,975 (down 1.8% over the past year, data through June 30, 2026) and Long Island at $609,323 (down 4.2% over the past year, data through January 31, 2026). For the other three -- Great Diamond Island/Diamond Cove, Little Diamond Island, and Cliff Island -- no reliable current ZHVI or median-sale figure could be confirmed. For Great Diamond specifically, Zillow does maintain dedicated listing pages and shows 25 recently sold transactions, but a specific current typical-value figure could not be pulled this pass due to fetch errors. For Little Diamond and Cliff Island, no comparable figure was found at all.

This is not a minor omission. These are genuinely thin, low-transaction micro-markets -- Little Diamond has as few as 3 total housing units on the entire island per the demographic snapshot above -- where a handful of annual sales can make any "median" statistically meaningless. Do not treat any price figure you encounter for Great Diamond/Diamond Cove, Little Diamond, or Cliff Island as settled. If you are pricing property on any of these three islands, go directly to a current listing or a local broker rather than relying on an aggregated median.

A Lobster Cooperative That May or May Not Still Be Running

Chebeague Island has the clearest documented lobstering identity of the five islands, built around a real, historically documented effort: Calendar Islands Lobster, launched September 14, 2009 by Dropping Springs LLC with support from the Island Institute, structured as a fishermen-owned, vertically integrated cooperative that grew to 29 participating fishermen in its second year, led by John Jordan and staffed largely by Chebeague residents. It invested in lobster-holding tanks, a Portland wharf lease, and a distribution boat. That 2009 founding is real and well documented -- but this page is not going to claim it is still operating today, because its current status was not independently confirmed. Separately, a business called Chebeague Island Lobster Co. (also styled Chebeague Lobster Co.) appears to be a more recently active operation, findable via a business listing and corporate registration, but its current operating status was not verified either. If a working lobster cooperative or seller is part of why you are looking at Chebeague, confirm who is actually selling lobster there right now rather than assuming either name is still in business.

Storm Damage: A Reasonable Inference, Not a Confirmed Fact

Back-to-back January 2024 storms caused serious, well-documented damage across Casco Bay -- Eagle Island lost three of four stone cribs supporting its pier and closed for the 2024 season; Lanes Island's campsite was threatened by erosion; Little Chebeague, Bangs, Crow, Whaleboat, Little Whaleboat, and The Goslings were all documented as damaged; a stewardship manager for the Maine Island Trail Association called it damage "beyond anything I've seen" in twelve years with the organization. What that source did not do is name Long Island, Chebeague, Great Diamond, Little Diamond, or Cliff Island specifically. Given how severe and widespread the documented damage was across the rest of the bay, it is reasonable background to assume these five islands were likely affected too -- but that is an inference, not a confirmed fact, and this page will not state specific storm damage to any of these five islands as though it were sourced and verified.

More broadly, no FEMA flood-zone boundary, no quantified erosion rate, and no island-specific resilience plan was confirmed for any of these five islands. Friends of Casco Bay maintains general resources on rising seas and storm surge for the bay as a whole, and that is genuine, relevant regional context -- but it is regional, not island-specific, and should not be mistaken for a finding about any one of these five properties.

Dining Rosters That Are Genuinely This Thin

Chebeague has the fullest small roster of the group -- the Chebeague Island Inn for fine dining, the Niblic at the island boat yard for coffee and sandwiches, and the Slow Bell Cafe. Great Diamond/Diamond Cove has Diamond's Edge Restaurant & Marina and the Diamond Cove General Store. Long Island has Byers & Sons Long Island Bakehouse and a general-goods Long Island Store, with no sit-down restaurant beyond those independently confirmed. Cliff Island has exactly one dining option: the Cliff Island Store & Cafe, a seasonal store-and-cafe combination. Little Diamond Island has none -- no restaurant, cafe, or store of any kind was found in this research pass, consistent with an island that has as few as 2 to 5 year-round residents.

This thinness is not a gap in this page's research -- it is an accurate reflection of how small these communities actually are. Small seasonal island businesses can also close or change hands quickly, so any name listed here should be checked against its own current listing before you plan around it.

The Ferry Fare Fight That Will Shape What It Costs to Live Here

Every one of these five islands depends entirely on Casco Bay Lines for groceries, mail, medical trips, and building materials -- Chebeague also has the separate Chebeague Transportation Company barge and passenger run from Cousins Island, but the other four rely on Casco Bay Lines alone. That makes a live 2026 dispute directly relevant to future cost of living here. Casco Bay Lines proposed raising peak-season round-trip adult passenger fares from $14 to $17, a 21% increase, following a 2024 fare hike (the first in 15 years) and a separate 2025 vehicle-fare increase. Hundreds of island residents filed a formal petition citing affordability concerns and improper public notice, and Maine's Office of the Public Advocate backed a state review. On June 16, 2026, the Maine Public Utilities Commission unanimously voted to open a full, formal adjudicatory investigation into both the financial justification for the increases and the rate-setting process itself -- with new fares remaining in effect for the summer season while that investigation proceeds and the PUC retaining authority to modify or reverse them.

Casco Bay Lines' own current rates page separately lists a $16.00 round-trip peak-season adult fare (child/senior/disabled $8.00) for April 18 through October 12, 2026, and an $8.00 off-peak round-trip fare (child/senior/disabled $4.00) for the rest of the year -- a flat rate that applies identically across all seven served stops, so the roughly two-hour round trip to Cliff Island costs the same as the short hop to Peaks Island. That $16 figure does not exactly match the $17 figure discussed in the proposal coverage, likely reflecting the gap between a proposed number and an adopted one, or a later adjustment. Re-verify the current fare directly with Casco Bay Lines before budgeting around either number, and watch for the outcome of the PUC investigation if a ferry-dependent island purchase is part of your plan.

What This Means Before You Decide

Put together, honestly: these five islands are not a single, uniform "Casco Bay island" product. Chebeague and Long Island have real, confirmed populations in the hundreds, their own secession histories, and Zillow-confirmed home values. Great Diamond and Little Diamond are small enough that even basic population counts from different sources disagree by a factor of six or more, land area was never confirmed, and no reliable price figure exists for either. Cliff Island calls itself the smallest year-round inhabited island in the bay, a claim that sits in real tension with Little Diamond's even-smaller numbers -- likely explained by the difference between an organized civic community and a private seasonal retreat, but not resolved by any source found here. Dining options range from a handful of real, named businesses on Chebeague down to nothing at all on Little Diamond. And every one of these islands now sits downstream of a live, unresolved ferry-fare dispute before the Maine Public Utilities Commission that will shape what it actually costs to get on and off any of them for years to come.

None of this is a reason to avoid these islands or a reason to buy on one of them -- it is the practical picture underneath the marketing copy, stated with its gaps left visible rather than papered over. Before any purchase, verify current population, land area, and price figures directly with a local broker or the relevant town/city assessor (Town of Long Island, Town of Chebeague Island, or the City of Portland for the three Portland-governed islands), confirm current Casco Bay Lines fares and schedules directly with the carrier, and follow the Maine Public Utilities Commission's fare investigation directly rather than relying on a single news snapshot. Nothing on this page is legal, tax, or relocation advice.