Just under 90 miles from Boston, on southeast corner of Cape Cod, lies Chatham Harbor and the Chatham Lighthouse. The original lighthouse was built in 1808. In 1887, after erosion created stability issues, the lighthouse was rebuilt, this time set further back. While the tower height reaches 48 feet, the light’s focal plane projects at approximately 80 feet above the ocean.
From its beginning to 1923, Chatham’s familiar beacons were famous to sailors for its Twin Lights. The original lighting configuration was two fixed lights. In 1857, the lights were upgraded to Fresnel lenses. This configuration was upgraded in 1923 with a clock mechanism to rotate a single lens. The second lens was moved to the Nauset Lighthouse in Eastam. In 1969, the U. S. Coast Guard upgraded the room and lantern, capable of projecting a much stronger beam. The old lens and room were donated to Chatham Historical Society. In 1982, the Coast Guard completely automated the lighthouse.