arc of visibility

The Admiralty chart of 1887 shows the "Arc of Visibility" of the lights from slightly west of south, through north, to slightly south of east.

The U.S. Coast Guard shall retain an easement for an Arc of Visibility and an unrestricted right of access in, to and across the Property to maintain, operate, service, repair and install equipment as necessary to support its aid to navigation mission.

It includes a set of cast-iron spiral stairs winding from the first floor to the lantern centered on the square gallery atop the tower, a decagonal cast-iron lantern was installed, and a new fixed white Fourth Order Fresnel lens with a 190 arc of visibility was assembled atop its cast-iron pedestal.