An Aid-to-Navigation

Q. Why are there so many lighthouses in North Carolina ?
Ideally, with lighthouses every 40 miles or so, one was nearly always visible to coasting ships. When one passed out of range, another would soon appear.

Q. Why is there a lighthouse here?
Extending about 14-20 miles offshore from Cape Hatteras are the shallow, shifting Diamond Shoals, a hazard to nearby navigation. By day or night, the Cape Hatteras lighthouse provided a navigational bearing, enabling ships to avoid the treacherous shoals. In the 19th century, “coasting” (sailing along the coast) was a simple, reliable form of navigation; and in case of trouble, the shore was within easy reach. Along the North Carolina coast, shipping also made good use of favorable currents - the Labrador Current, flowing south near shore, and the Gulf Stream, flowing north a bit farther out, provided additional speed. The Outer Banks of North Carolina are widely known as the Graveyard of the Atlantic. One account says 230 ships of over 50 tons sank here from 1866 to 1945. Another says well over 2200 ships have sunk off the Outer Banks since Europeans first arrived.

Q. Is the Cape Hatteras lighthouse still a functional navigational aid?
Yes. It is now automated.

Q. With today's navigational technology, is it still a useful aid-to-navigation?
Yes, though not to the same extent it once was. It provides confirmation of modern navigational methods and a landmark for local boat traffic - seen from a few miles out to sea, this coastline has few distinguishing features.

Q. Why is it painted with black & white stripes?
The stripes serve as a daytime identification aid or daymark allowing mariners to distinguish between the lighthouses (see below for more information on daymarks).

In North Carolina, the Currituck Beach Light is unpainted red brick; Bodie Island is banded black and white; Cape Hatteras is black and white spiral stripes; Ocracoke is white; and Cape Lookout is black and white checkerboard. No evidence has been found to indicate that the checkerboard or diamond pattern was originally intended for the Cape Hatteras Light at Diamond Shoals, despite a popular folk story that some bureaucrat messed up the work order.

Q. What is meant by the term “daymark” and how does it apply to lighthouses?
All lighthouses are daymarks. The term simply means a fixed, constant, identifiable feature that can be used by a navigator during daylight hours to assist in determining a ship’s location along a coastline.

Generally, the shapes of the tower and dwelling, the advertised color and the geological background such as cliffs, rocks, hillsides, etc. provide adequate data to the mariner to assist with location determination. Towers can also be painted, often in solid colors that contrast with their natural backgrounds making them more visible. So, a lighthouse that is built of stone on a rocky island would most likely be painted white; a lighthouse near a town with numerous white buildings would probably be painted red.

However, problems can occur in areas such as the central/southern Atlantic coast of the United States. In general, the coast is topographically quite flat with few, if any, outstanding natural features to assist the mariner. Compounding this issue, the tall coastal towers, built primarily between the 1850s and 1870s, were virtually identical in appearance from a distance at sea. Therefore, to make them identifiable, they each received distinguishable daymarks – usually paint, though some towers were left unpainted. Only certain colors – black, white and red - were used because these are the ones that would stand out the best against the background. Therefore, along the Outer Banks, the tall coastal lighthouse daymarks are: Currituck Beach Light - unpainted red brick; Bodie Island - banded black and white; Cape Hatteras - black and white spiral stripes; and Cape Lookout - black and white checkerboard.

Q. Has the Cape Hatteras lighthouse always been black and white spiral striped?
No. This paint job did not exist until 1873.

The 1803 sandstone tower appeared to be white. This may have been due to the natural color of the stone or a whitewash coating. This changed when the tower was extended with a brick addition in 1854. The lower 70 feet of the tower remained white and the top 80 feet was red. It was probably red on top to contrast with sky and white on bottom to contrast with the vegetation. It was painted with a cement-based brick wash.

The 1871 Report of the Light-House Board indicates that, when it was first painted, the top part of the current tower was painted red and the bottom part white. Other reports say that the whole tower wasoriginally red. In any case, the stripes were painted in 1873. There are two black and white stripes on the tower, each stripe circles the lower tower 1 1/2 times, and all are wider on the bottom than on the top. It is not known exactly how the stripes were laid out, but it could have been done using a combination of pre-calculated dimensions, plumb bobs, and taut lines. Originally, the keepers painted the tower using bosun’s chairs, taking up to 4 months every 6-10 years. Modern painting contractors use a window washer type platform.

From 1936-1950, the official tower was a steel structure, though many mariners still used the 1870 lighthouse as a daymark.

Q. How can lighthouses be told apart at night?
Lights can be distinguished by their “characteristic” or nightmark. Their lights may appear to either glow constantly (fixed) or flash at different rates. Here, the rate is every 7 1/2 seconds, though it has varied over the years. Throughout the centuries, mariners have had lists of lights - tables that list the nation's navigational aids including the lighthouses, their exact positions, and their daymarks and light characteristics.