Machias Seal Island

Island Disputed seabird island with puffin colonies

Machias Seal Island sits at the edge of the Gulf of Maine with a lighthouse and nesting Atlantic puffins; birdwatching boat trips run from New England and the Canadian Maritimes despite a territorial dispute.

Machias Seal Island is a small, rocky island in the Gulf of Maine that is claimed by both Canada and the United States. It is best known for its lighthouse and dense seabird colonies.

Boats from nearby coasts run sightseeing trips to view nesting Atlantic puffins, razorbills and other colonial seabirds on the island’s ledges; landing is controlled and often limited. The lighthouse complex is the principal human structure on the island and is used as a navigational aid.

The island has long been part of a bilateral territorial dispute between Canada and the United States, and the sensitive status affects governance and access arrangements. Conservation of seabird habitat is a key priority for managers and researchers.

Machias Seal Island lies in the Gulf of Maine between the coasts of Maine and New Brunswick, in open coastal waters off northeastern North America.

Territorial status: Sits in a maritime area claimed by both Canada and the United States, making the island notable for an ongoing territorial dispute between the two countries.
Seabird colonies: The island supports large seabird colonies that are most visible during the breeding season, typically in late spring and summer.

What to See #

Lighthouse: The small lighthouse complex that serves as a navigational aid in the Gulf of Maine and is situated on the island; the structure and surrounding buildings are focal points for wildlife viewing from boats.
Seabird nesting areas: Sea cliffs and rocky ledges used by nesting seabirds, including puffins and other colonial species, which are the main attraction for visitors arriving by boat.

How to Get to Machias Seal Island #

Machias Seal Island lies offshore from the Maine/New Brunswick coast and is reached only by boat. Seasonal wildlife and bird‑watching boat trips operate from harbours such as Cutler, Maine, and from ports in New Brunswick (Grand Manan area); many visitors view the island from vessels rather than landing. Landing access and visits are controlled, so go with a licensed operator and check permissions and schedules in advance.

Tips for Visiting Machias Seal Island #

Plan a visit in the seabird breeding season (roughly late spring-summer) to see Atlantic puffins and other nesting birds at their most active.
Access is boat‑based: licensed operators run viewing trips from nearby harbours (Cutler, ME and Canadian ports); most visitors view the island from the water rather than landing-check operator schedules and book in advance.
Because the island is a sensitive breeding site, follow your captain's and guide's instructions, stay on the vessel during viewing approaches, and bring binoculars/telephoto optics rather than attempting to get closer.