The dangerous shoals and currents off Chatham led Congress to appropriate funds for a lighthouse there in 1806, and the first light was completed in 1808 as a pair of wooden octagonal towers about 40 feet high, set 70 feet apart on movable skids so they could be repositioned with the shifting sand bars and provide a range for ships. Samuel Nye, appointed by President Thomas Jefferson, was the first keeper. After the wooden towers deteriorated, the Treasury Department funded two brick towers and a brick keeper's house in 1841. Collins Howes, then Simeon Nickerson, and after his death his wife Angeline served as keepers, with Angeline retaining the post after President Taylor ruled in her favor. In 1857 the lights received fourth-order Fresnel lenses showing fixed white light fueled by lard. Josiah Hardy, keeper from 1872 to 1900, reported severe erosion in front of the lights, and by 1877 the towers stood only 48 feet from the edge, prompting construction of two 44-foot cast iron towers with brick interiors. The old south tower fell to the beach on December 15, 1879, and the north tower followed 15 months later. Twin lights became unnecessary with rotating lights in the early 20th century, and in 1923 the north light was moved to Eastham while the remaining tower received a rotating lens powered by kerosene. The light was electrified in 1939, and in 1969 its Fresnel lens and lantern room were replaced with a larger lantern for modern rotating aero beacons. Installed in 1994, the present light displays two white lights every 10 seconds visible 24 nautical miles at sea. The lighthouse complex also serves as headquarters for Coast Guard Station Chatham, whose waters include the area from Truro south to halfway between Monomoy Island and Nantucket, west into Nantucket Sound, and north to Hyannis; the station is especially noted for the February 18, 1952 rescue in which the crew of CG36500, led by Bernard Webber, saved 32 crew members from the stern section of the broken tanker Pendelton during a violent snow storm.