It has been used for military training for over 150 years and is part of the Dungeness, Romney Marsh and Rye Bay Site of Special Scientific Interest.
[1] Also, red lights are shown at restricted times if there is poor weather.
The danger area extends out to sea, and mariners sailing to and from Rye Harbour must pass south of the Stephenson Shoal to avoid it.
[1] Until the 90s it was home to the wreck of what is likely the only surviving Gun Carrier, 3-inch, Mk I, Churchill (A22D).
It is principally a target railway,[4] although it also carries personnel and equipment around the facility.