Beach Erosion Reality: Casco Bay Islands, ME
Long Island, Chebeague Island, Great Diamond Island, Little Diamond Island, and Cliff Island are five separate, ferry-access communities in Casco Bay, each reached by Casco Bay Lines from downtown Portland (Chebeague also has its own second ferry operator, the Chebeague Transportation Company, running a short crossing from Cousins Island in Yarmouth). This page is about those five islands, not Peaks Island -- Peaks is the largest and most heavily served of the Casco Bay islands and already has its own dedicated coverage elsewhere on this site, so it's mentioned here only as brief context. What follows is an honest look at what is and is not actually documented about beach and shoreline condition on these five islands: a real 1972 oil-spill history on Long Island, real but broader storm damage across Casco Bay in January 2024, and a genuine gap in island-specific erosion data that this page will not paper over with an invented number.
Five Small Islands, Directly Exposed to Open Bay
Unlike a mainland beach town with a road-connected seawall or a funded dune-rebuild project, each of these five islands sits out in Casco Bay with no bridge to the mainland and no mainland-scale coastal-defense infrastructure behind it. Long Island's incorporated town is mostly water -- 32.10 of its 33.52 square miles -- with the main island itself commonly described as roughly three miles long and about a mile wide, directly facing the open bay. Chebeague, the largest of the five, runs nearly five miles long and a mile and a half wide. Great Diamond, Little Diamond, and Cliff Island are smaller still, and Cliff Island sits at the far end of Casco Bay Lines' route, commonly cited at roughly 60 to 120 minutes one-way from Portland depending on stops.
That geography matters for a simple reason: every one of these islands' emergency response, evacuation planning, and post-storm supply and repair logistics runs through Casco Bay Lines (and, for Chebeague, also the Chebeague Transportation Company's barge). That is a genuinely different risk profile than a bridge- or road-connected coastal town, where a storm-damaged seawall can at least be trucked in and rebuilt on a normal construction timeline. No island-specific evacuation plan or storm-response capability for any of these five islands was independently confirmed for this page, but the ferry-dependency itself is a real, structural fact worth naming plainly.
Long Island's 1972 Tamano Oil Spill: Real History, Not Erosion
Long Island has its own documented environmental history that is worth separating clearly from erosion, because it is a different kind of event. In 1972, the tanker Tamano ran aground and spilled oil that contaminated West Beach on Long Island -- a real, sourced incident, not a rumor. It followed a failed 1969 proposal by King Resources to build a supertanker port near the island, a plan islanders pushed back against before the spill happened. Together, those two episodes are part of why Long Islanders describe their relationship with outside industrial pressure the way they do -- but an oil spill is a contamination event, not a beach-erosion event, and this page won't blur the two together.
What that history does not tell us is anything about West Beach's current shoreline condition, sand loss, or erosion rate more than five decades later. No follow-up study on West Beach's post-spill or current erosion condition was found for this page, so none is claimed here. It's real, relevant beach-condition history -- and it's a separate question from whether, or how fast, Long Island's beaches are eroding today.
The January 2024 Storms: Real Damage to Casco Bay, Not Confirmed Here
Two back-to-back storms hit the Maine coast in January 2024, and the damage across Casco Bay was real and well-documented in several places. Eagle Island, a state historic site, lost three of the four stone cribs supporting its pier and suffered significant erosion on its southern end, closing it for the entire 2024 season. Lanes Island, off Freeport, had a campsite directly threatened by beach erosion. Little Chebeague, Bangs, and Crow Islands were also documented as damaged, along with Whaleboat Island, Little Whaleboat, and the Goslings in Middle Bay off Harpswell, and storm-felled trees blocked trail systems on Monroe and Sheep Islands. Maria Jenness, stewardship manager for the Maine Island Trail Association, called the damage "beyond anything I've seen" in her twelve years with the organization.
Here is the honest, important gap: none of the reporting behind this page named Long Island, Chebeague Island, Great Diamond Island, Little Diamond Island, or Cliff Island specifically as storm-damaged in January 2024. Given how severe and widespread the damage was elsewhere in the same bay, it's a plausible inference that these five islands' own shorelines took some hit from the same storms too -- but it is an inference, not a confirmed fact, and this page is not going to state specific erosion or storm damage to any of these five islands' own beaches as if it had been documented, because it wasn't found in the sourced reporting reviewed for this page.
No Seawalls, No Dune-Rebuild Projects: The Honest Infrastructure Picture
Other markets on this site -- Wells and Old Orchard Beach among them -- have real, named seawall and dune-rebuild projects to point to. Nothing comparable turned up for Long Island, Chebeague, Great Diamond, Little Diamond, or Cliff Island. That's not a gap in this page's research so much as a reflection of what these islands actually are: small, thinly populated, ferry-access communities without the tax base, road access, or scale that typically funds mainland-style coastal-engineering projects.
Regionally, Friends of Casco Bay maintains its own public resource on rising seas and storm surges in Casco Bay, and it addresses the bay broadly rather than any single island. No island-specific erosion rate, FEMA flood-zone boundary, or resilience-plan finding for any of these five islands was independently confirmed for this page. If a rate or finding shows up somewhere else with one of these five islands' names attached, treat it as unverified until it's checked against a primary source.
What This Means Before You Decide
Put together, honestly: these five Casco Bay islands sit directly exposed to open water with no bridge and no mainland-scale seawall or dune-rebuild infrastructure behind them. Long Island carries a real, documented 1972 oil-spill history at West Beach, distinct from erosion. The January 2024 storms did real, well-documented damage elsewhere in Casco Bay -- Eagle Island and Lanes Island among them -- but no source reviewed for this page confirmed specific erosion or storm damage to Long Island's, Chebeague's, Great Diamond's, Little Diamond's, or Cliff Island's own beaches. That absence of island-specific data is itself the honest finding here, not a reason to guess.
Anyone weighing a purchase, a rental, or simply a visit around one of these islands' beaches should go directly to the Maine Geological Survey and Friends of Casco Bay for the most current regional coastal-change information, and, for anything address-specific, bring in a local coastal geologist or the relevant town's own office (Long Island's or Chebeague Island's town government, or the City of Portland for Great Diamond, Little Diamond, and Cliff Island). This page is independent research, not engineering, legal, or insurance advice.
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Get a Free Agent Referral →Independent research. No ads. No sponsored listings. Long Island's 1972 oil spill from the tanker Tamano at West Beach, and the 1969 failed King Resources supertanker-port proposal that preceded it, are real, documented events (Wikipedia: Long Island, Maine); no post-spill or current West Beach erosion study was independently confirmed for this page. The January 2024 back-to-back Maine storms caused real, well-documented damage across Casco Bay -- including Eagle Island's pier and southern-end erosion damage and Lanes Island's threatened campsite -- per the Harpswell Anchor's reporting on sea-kayaker damage documentation; that reporting did not name Long Island, Chebeague Island, Great Diamond Island, Little Diamond Island, or Cliff Island specifically, and this page treats any storm effect on those five islands' own beaches as a plausible but unconfirmed inference, not a documented fact. Friends of Casco Bay maintains a real public resource on rising seas and storm surges in Casco Bay, addressing the bay generally rather than any single island. No seawall, dune-rebuild, or comparable mainland-scale erosion-mitigation project was found for any of these five islands, unlike Wells or Old Orchard Beach elsewhere on this site. No FEMA flood-zone boundary, NFIP repetitive-loss count, or quantified erosion rate for Long Island, Chebeague Island, Great Diamond Island, Little Diamond Island, or Cliff Island was independently confirmed. This page is independent research, not engineering, legal, surveying, or insurance advice; for any address-specific coastal erosion assessment, contact the Maine Geological Survey and a local coastal geologist directly.