Deer Island Light

Deer Island Light

Library of Congress

Quick Facts

Location:

South of Deer Island

OPEN TO PUBLIC:

No

While it no longer exists, Deer Island Light sat 500 yards south of Deer Island Point on the north side of the entrance to inner Boston Harbor. Ships using the Broad Sound Channel in the harbor pass the site of Deer Island Light.

In 1832, the Boston Marine Society petitioned Congress to erect an unlighted stone beacon at the site south of Deer Island Point. Congress approved the construction of the beacon, and it remained there for nearly 60 years.¹

Later, in 1886, Congress appropriated funds for a lighthouse to replace the daybeacon at the request of the US Lighthouse Board. Workers sunk a 30-foot caisson lighthouse into six feet of water on the spit. The caisson base, or watertight retaining structure, was filled with concrete and had space for a basement and cisterns. On top of the caisson, workers built a four-story cast iron structure encircled by a roofed gallery. At the end of construction in 1890, Deer Island Light stood at 57-feet tall and contained living quarters, a light, and a fog bell.²

However, Deer Island Light deteriorated quickly—as early as 1902, the caisson base needed to be patched and banded for reinforcement. After decades of further deterioration and erosion of the base, workers added a protective wall of sheet piling in 1937.³

During a severe storm in the winter of 1972, the tower began to tip, causing the entire lighthouse to be abandoned. Deemed unsafe, the Coast Guard believed repairs would be too expensive to rebuild. The Massachusetts Historical Commission deemed it not eligible for the National Register of Historic Places. As a result, the lighthouse was demolished in 1982.⁴

A white fiberglass tower replaced the original on the old foundation. However, mariners could not see the white tower against the background of Deer Island. As a result, the Coast Guard replaced the white tower with a brown fiberglass tower. In 2015-2016, the Coast Guard dismantled the brown tower and replaced it with a modern, automated LED navigational aid 100 feet away.⁵  

Prepared by Nancy S. Seasholes, 2009. Updated 2025.

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Footnotes

1. Jeremy D'Entremont, "Deer Island Lighthouse," Deer Island Lighthouse - NEW ENGLAND LIGHTHOUSES: A VIRTUAL GUIDE, accessed November 17, 2025.
2. Ibid. 
3. Ibid.
4. Ibid.
5. Ibid.