Carpender pointed out that the lights were too close together, causing them to blend and appear as a single light at a short distance. Also being horizontal they “were likely to come into a range with each other, by which they also appear single.” Carpender’s remedy for this was to convert them from horizontal to perpendicular beams, but his suggestion was never carried out.
In 1842 the Gurnet lighthouses were rebuilt and the new structures, while still of wood, each had a distinctive design. In 1871 the lights were of the sixth order and were declared by the Lighthouse Board to be “entirely too small” and “readily mistaken for the lights in a dwelling house, when they can be seen at all.” Their distance apart was also too short to afford an efficient range. Nothing ever came of the recommendation that they be replaced with fourth-order lights “separated by a proper distance for an effective range.”
After 1851, Thomas Treble followed Joseph Burgess as keeper. His successors were William Sears, Milton Reamy, Edward S. Gorham, Henry L. Pingree, and A. S. Eisener. Keeper Davis in 1929 had a long list of rescues to his credit, and keeper Reed rescued the crew of the mine sweeper U. S. S. Swan stranded on Gurnet Beach on November 28, 1930.
Gurnet Light had lost its importance as a light as Plymouth Harbor lost its shipping traffic over the years. Not until Cape Cod Canal was opened in 1914 did the lighthouse again become an important coastal beacon.
In 1924 the northeast tower was discontinued and the station is now described as a white, octagonal, pyramidal tower, with white dwelling, 39 feet above ground and 102 feet above water. Its 700,000 candlepower, fourth-order electric light shows group flashing white every 20 seconds and is visible for 16 miles. An air diaphragm horn blasts for 3 seconds every 15 seconds during fog. (5)
Little Sable Lighthouse, a white brick tower, 107 feet in height, connected to the keeper’s dwelling, and surrounded by a picturesque group of trees, stands on a point about 10 miles south of Pentwater. The lighthouse was built in 1874, and the light now shown from the tower is fixed and flashing white, the flashes being of 40,000 candlepower. Several miles to the northward is Big Sable Lighthouse, on the point of that name, distinguished at night from Little Sable by having a fixed white light, and by day by the color of the tower, banded in black and white. Big Sable Lighthouse is the same height as the tower at Little Sable, but was erected in 1867. (1) (2)