Diamond Shoals—the name fills mariners with dread. With the advent of GPS, depth finding devices, and reliable weather forecasts, it is no longer the death trap it was for hundreds of years. Yet it is still a place that ships avoid if they possibly can.
Within the space of 100 yards or less water depth goes from 35 or 40 feet to 12 feet, and then the NOAA Chart for the Cape Hatteras Chart for Diamond Shoals notes, “Hydrography (water depth) is not charted for Diamond Shoals due to the changeable nature of the area. Navigation in the area is extremely hazardous to all types of craft.”
It is fitting, then, that Cape Hatteras is considered the heart of the Graveyard of the Atlantic.
Diamond Shoals is not one shallow deposit of sand extending 14 miles east and south from the Point at Cape Hatteras. Rather it is three distinct shoals. Hatteras Shoal is the closest to Cape Hatteras, Inner Diamond Shoal is next and Outer Diamond Shoal is the farthest from land. Between the shoals, there are sloughs or channels, although the locations and depths of the sloughs are constantly changing as ocean currents shift the seabeds of the sandy shelves.
It is unclear where the name originated. Its first official use appears to be 1948 when the U.S. Board of Geographic Names assigned the name Diamond Shoals to the entire series of shoals and gave names to the individual shoals and sloughs.
There are a number of reasons why so many ships met their doom at Diamond Shoals. During the age of sailing ships and even today, ships leaving northern ports bound for Europe will often sail south along the coast to pick up the Gulf Stream as it begins its eastern flow toward Europe at Cape Hatteras. There is also considerable coastal shipping traffic as well, and ships sailing from the south have taken advantage of the north-flowing Gulf Stream for years.
In either case, though, ships hug the coastline until they reach Cape Hatteras.
When sailing ships plied the ocean even the smallest navigational error could bring them to a collision with Diamond Shoals. Weather was also a factor, with coastal storms and fog a constant danger.
Early in our nation’s history, the federal government recognized the danger of Diamond Shoals and authorized a lighthouse at Cape Hatteras as early as 1794 although it took nine years for construction to begin.
The first Cape Hatteras Lighthouse was an abysmal failure. In 1851 Navy Lt. David D. Porter, in a report on the lighthouse wrote, “Hatteras light, the most important on our coast is, without doubt, the worst light in the world… The first nine trips I made I never saw Hatteras light at all, though frequently passing in sight of the breakers, and when I did see it, I could not tell it from a steamer’s light, excepting that the steamer’s lights are much brighter.”
The lighthouse was raised and a first order Fresnel lens was placed in it before the Civil War. Porter noted that was an improvement but felt more improvement was needed.
After the Civil War, Congress took a hard look at what was needed at Cape Hatteras and Diamond Shoals and appropriated funds for the Cape Hatteras Lighthouse that still warns mariners of danger.
Even with the new Cape Hatteras Lighthouse with a beam that could be seen more than 20 miles out to sea, Diamond Shoals continued to be a threat to shipping, but no danger and no destruction of ships could match what would happen in first WWI and then WWII.
The pattern of hugging the coast to take advantage of the Gulf Stream is well-known in the world of shipping, and in WWI and WWII German U-Boats, knowing the U.S. and allied shipping would be close to the shoreline and have no place to run, made the area one of their favorite hunting ground.
According to the National Marine Sanctuary, U-Boats sank 10 ships off the Outer Banks coast in WWI. The Mirlo, one of the most historic rescues in US Coast Guard history was one of those ships.
It was WWII when the true horror of war came to North Carolina shores. Between January of 1942 and 1945, the National Marine Sanctuary puts the number of allied ships lost to German U-boats at 90, almost all of them from 1942-1943,
Although some of those ships were torpedoed off Cape Lookout to the south, most of the damage to shipping occurred from Ocracoke and north…and much of that was centered around Cape Hatteras.
U-Boat captains, knowing that ships would have to congregate at Cape Hatteras but could not be too close to shore because of Diamond Shoals, placed themselves between deep waster and the shoals and simply waited.
US Naval commanders were slow to respond to the threat, believing at first that U-boats would not attack along the Eastern Seaboard and even after attacks began. did not initially order merchant ships to turn off their running lights at night and to zigzag to create a more difficult target. for the submarines. It also took six months for the nation to realize that cities, towns and homes had to have their lights blacked out. Until blackouts were instituted, the U-boat captains could clearly see ships silhouetted against the shoreline at night.
By June of 1942, however, naval commanders were heeding the advice of their British counterparts and had instituted convoys and air patrols and the threat from U-boats quickly diminished.