Buying on the Other Casco Bay Islands: Five Markets, Five Different Sets of Rules

The General Process Is Standard Maine Practice

A purchase on any of these five islands follows the same general shape as any other Maine residential transaction: a buyer makes an offer, typically through a licensed Maine real estate agent or broker; the parties negotiate; a title search is conducted to confirm clear ownership and surface any liens or easements; standard Maine seller-disclosure norms apply; and the deal moves toward closing once financing, inspection, and title contingencies are cleared. None of that is unique to Long Island, Chebeague, Great Diamond, Little Diamond, or Cliff Island -- it's the same generic process used across the state.

This page does not state a specific closing timeline, name a specific title company or attorney, or quote inspection and appraisal fees, because those vary by transaction and by the professionals a buyer chooses. A Maine-licensed real estate agent or broker and a real estate attorney who has actually closed a transaction on one of these specific islands -- not just "an island somewhere in Maine" -- are the right sources for current costs, timelines, and required disclosures.

Which Town Hall You Deal With Depends Entirely on Which Island

This is the single most consequential fact for a buyer on these five islands, and it splits them cleanly into two groups. Long Island and Chebeague Island are each their own separate, incorporated Maine towns, with their own town offices and their own assessors. Long Island seceded from the City of Portland on July 1, 1993, following a 1990 Portland property-tax revaluation that residents argued raised their taxes out of proportion to the municipal services they actually received. Chebeague Island seceded from the town of Cumberland, Maine, on July 1, 2007, after 184 years as part of Cumberland -- a different trigger entirely, driven by protecting the island's own small elementary school from Cumberland-district downsizing pressure, and authorized by a specific Maine Legislature public law (PS Law, Chapter 47) following an April 5, 2006 legislative vote.

Great Diamond Island, Little Diamond Island, and Cliff Island, by contrast, have no secession story at all -- all three are, and always have been, part of the City of Portland. A buyer on any of these three islands deals with Portland's own municipal departments: Portland's own assessor for property valuation, Portland's own permitting and code-enforcement offices for any renovation or new construction, and Portland's own tax rate, the same way a buyer in any other Portland neighborhood would. That's a genuinely different administrative experience than buying on Long Island or Chebeague, where the town office you'd call is a small, separate, island-specific municipal government rather than a department inside a city hall on the mainland.

Worth naming as context, not as something this page re-covers: Peaks Island is also part of the City of Portland, governed through Portland's own departments with an advisory Peaks Island Council rather than an independent town government -- the same administrative arrangement a buyer would find on Great Diamond, Little Diamond, or Cliff Island. Peaks Island's own buying-process page on this site covers that in depth for Peaks Island specifically; it isn't repeated here.

This page does not state current mill rates, assessed-value practices, or permitting fees for either Long Island's or Chebeague Island's own town offices, or for Portland's departments as they apply to Great Diamond, Little Diamond, or Cliff Island, because those figures change and were not independently confirmed here. Before making an offer, confirm current tax rates and permitting requirements directly with the relevant office: the Town of Long Island, the Town of Chebeague Island, or the City of Portland's assessor and permitting departments, depending on which island you're buying on.

Ferry Access Is a Real Buying Consideration, and It Varies a Lot by Island

Every one of these five islands is served by Casco Bay Lines from downtown Portland, but the practical experience of that ferry connection is not the same island to island. Trip lengths vary dramatically: Long Island's run typically lasts 30 minutes to an hour depending on route and stops; Chebeague's Casco Bay Lines mail-boat route to Chandler's Cove runs roughly 60-90 minutes; and Cliff Island's run is the longest of the group, commonly cited at roughly 60-120 minutes one-way depending on route and freight stops, with five daily round trips operating year-round.

Chebeague Island is also the one island in this group with a genuinely distinct second option: the Chebeague Transportation Company (CTC) runs a much shorter, roughly 15-minute passenger crossing from Cousins Island in Yarmouth to the island's Stone Wharf, plus a vehicle and freight barge by reservation from April through November. That two-operator, two-route setup is unique among these five islands, and it means a Chebeague buyer researching commute times or move-in logistics should look at both the Yarmouth-side CTC option and the Portland-side Casco Bay Lines option before assuming one ferry schedule applies.

The practical buying implication is the same one that applies on any ferry-only island, just amplified by how long some of these crossings are: every home inspector, appraiser, or contractor who needs to physically visit the property has to get there by boat, on a real schedule, not by driving up on a convenient morning. That matters more on a 60-120 minute Cliff Island crossing than on a shorter hop, and it's worth asking any professional you hire whether they've worked on this specific island before and how they plan to get themselves and their equipment there. This page does not state current Casco Bay Lines or CTC schedules or fares, since both change; confirm directly with the carrier before scheduling around them.

Real Estate Data: Two Islands With Real Numbers, Three Where You Should Expect a Gap

The real estate picture across these five islands is genuinely uneven, and a buyer should go in expecting that rather than assuming every island has a comparable, published home-value figure. Chebeague Island has a confirmed Zillow typical-home-value (ZHVI) figure of $666,975, down 1.8% over the past year. Long Island has a confirmed ZHVI figure of $609,323, down 4.2% over the past year. Both of those are real, sourced numbers a buyer can use as a starting reference point, though as with any ZHVI figure they're an estimate, not an appraisal.

For Great Diamond Island and its Diamond Cove neighborhood, no current, independently confirmed ZHVI figure could be obtained for this page -- the data fetch was blocked by proxy errors during research, not because no market exists. Zillow does maintain dedicated listing pages for Great Diamond Island and Diamond Cove and shows a real volume of recently-sold transactions there, so treat the absence of a figure here as a research gap to fill in with a current Zillow lookup or a local agent, not as evidence the market is illiquid.

For Little Diamond Island and Cliff Island, this page states no home-value figure at all, deliberately. Both are genuinely thin, low-transaction markets -- Little Diamond has as few as three total housing units by one demographic count -- where a handful of annual sales, or fewer, can make any "median" or "typical value" statistically meaningless rather than merely imprecise. Any number you encounter elsewhere for either island should be treated skeptically until you can trace it to a specific, dated source and a specific, verifiable transaction count.

A general pattern worth naming across all five islands: a documented, meaningful share of purchases here are made by off-island or out-of-state buyers acquiring the property as a seasonal retreat rather than a year-round home, a pattern tied directly to the island housing-affordability pressures discussed below. That's worth factoring into your own comparison shopping -- the "typical" buyer competing for a given listing may not be a year-round local household.

Little Diamond Island's Winter Water Shutoff: A Real Habitability Question

One infrastructure detail is specific enough, and consequential enough, to call out on its own: Little Diamond Island's water supply is shut off during the winter months, which directly limits year-round habitation there. If you're evaluating a property on Little Diamond with any intention of living there outside the summer season, this isn't a minor seasonal inconvenience -- it's a structural reason the island functions today as a predominantly private, seasonal-cottage community rather than a year-round neighborhood, and it should shape both your intended use of the property and the questions you ask before making an offer. Confirm the current state of water service, and any plans (or lack of plans) to change it, directly with the seller, a local contractor, or the relevant utility before assuming winter occupancy is realistic.

Housing Affordability: A Documented Regional Crisis Worth Understanding Before You Buy

A July 2025 Portland Press Herald investigation into Maine's unbridged islands -- explicitly naming Chebeague, Long Island, and Cliff Island among the Casco Bay islands it examined -- documented a real, ongoing island housing shortage. Its findings included a median island resident age of 56, versus 44 statewide; housing costs pushed up in part by outside buyers converting year-round homes to seasonal use; island construction costs running roughly 30% higher than mainland costs because of barge transport and infrastructure constraints; and a limited land supply further constrained by conservation easements.

Chebeague Island has a specific, named response worth knowing about if you're evaluating housing supply and community character there: the Chebeague Island Community Association (CICA) has run real affordable-housing projects for more than a decade. That includes a modular duplex at 43 School House Road, built with a $350,000 MaineHousing grant and installed in May 2012, occupied by two island families by that fall; a 2013-2014 rent-with-option-to-purchase house at 226 South Road; and a second modular duplex at 553 South Road, on land donated by Stacie and Toby Webb, built with Dirigo Homes and installed in May 2025, with tenants expected to move in during fall 2026. More broadly, MaineHousing's Affordable Housing Initiative for Maine Islands has funded 49 units across 10 islands, with individual grants of up to $840,000.

The practical relevance for a buyer is this: the same off-island, out-of-state seasonal-buyer demand that shapes prices on these islands is also a documented driver of the housing-supply pressure facing year-round island residents. That doesn't change the mechanics of your own purchase, but it's useful context for understanding why local housing stock feels scarce, why year-round neighbors may view seasonal buyers with some ambivalence, and why a project like CICA's exists in the first place. This page does not have confirmed, current figures for Great Diamond Island or Little Diamond Island's own housing-affordability picture -- no dedicated 2025-2026 civic reporting on either island's housing supply was found, likely reflecting how small and heavily seasonal both populations already are.

Putting the Purchase Process Together

Strip away the island-specific wrinkles and a purchase on any of these five islands is a standard Maine residential transaction: an offer, a title search, standard disclosure norms, and a closing, handled by a licensed Maine real estate agent or broker and, where warranted, a real estate attorney. What genuinely changes from island to island is which town office or city department you deal with (Long Island's and Chebeague Island's own town governments versus the City of Portland's departments for Great Diamond, Little Diamond, and Cliff Island), how long and how frequent your ferry connection is, and how much reliable real estate data actually exists for the specific island you're looking at -- solid on Chebeague and Long Island, a confirmed gap on Great Diamond, and effectively unmeasurable on Little Diamond and Cliff Island.

Before making an offer, work with a Maine-licensed real estate agent or broker who has direct experience with the specific island you're buying on, confirm current tax rates and permitting requirements with the correct town office or Portland department, check current Casco Bay Lines (and, for Chebeague, Chebeague Transportation Company) schedules directly with the carrier when scheduling any pre-purchase visit, and consult a Maine real estate attorney about title, disclosure, and closing specifics for your transaction. Nothing on this page is legal or real estate advice, and it should not substitute for advice from a licensed Maine agent, broker, or attorney familiar with your specific island and your specific purchase.