Sharps Island Light

Oct. 15, 2019

Sharps Island Light, southern end of Tilghman Island, Chesapeake Bay, Maryland

Originally built in 1882 on a caisson foundation, replaced and updated several times, the current structure is a sparkplug style light which is tilted from an ice flow in 1977.


Location:  Chesapeake Bay, off the entrance to the Choptank River
Date Built:  Original, land-based lighthouse – 1838,  Screw-pile light – 1866, Current caisson light – 1882
Type of Structure:  Caisson with cylindrical iron dwelling / tower (sparkplug)
Height:  54 feet above mean high water
Characteristics:  Flashing white with one red sector
Foghorn:  Yes
Builder:  Builder’s Iron Company of Providence, Rhode Island
Appropriation:  $35,000
Range:  9 miles
Status:  Standing and Active

Historical Information: 

  • Sharps Island Light marks the shoal of what once was a 900+ acre island in the Chesapeake Bay off the entrance to the Choptank River. The current structure is the third Sharps Island lighthouse and marks both the entrance to the Choptank River and the main shipping channel of the Chesapeake Bay. The original structure was built in 1838 using a $5,000 appropriation from Congress. At first a tower with detached keepers dwelling was envisioned, similar to the one at Bodkin Island, and a contract for such a light was awarded to Thomas Evans (who had co-built the Bodkin Island Light). However, it was soon recognized that there were erosion issues associated with the Island. Rather than combating this through the erection of expensive jetties and bulkheads, the Fifth Auditor of the Treasury, Stephen Pleasonton, directed that the light should be re-designed. The result was a wooden structure, incorporating the keepers dwelling and a roof-top lantern, built on wheels so it could be moved if necessary. Evans agreed to surrender his earlier contract and build a structure of the new design. Pleasonton thereafter turned down any requests for barriers to prevent soil erosion. The light was commissioned in late 1838. After only, ten years, much of the Island had been reclaimed by the Bay and in late1848 additional acreage had to be purchased and the light was moved inland. This unique original structure served for 27 years. In 1855, its Argand-style lighting system was replaced with a fifth order Fresnel lens. By 1865 the waters had reached the light again. By that time the administration of U.S. lights had been reorganized under the Lighthouse Board. Rather than attempting to move the light again, the Board sought and received funds for a new light of the screw-pile design. Several requests to Congress had to be made before funding was received and by that time the situation was urgent. During construction of the new light, water had reached the light on shore and it had to be discontinued. A temporary wooden tripod was constructed which exhibited a steamers lens while the new light was being built. (The old lighthouse structure was soon lost.) The new hexagonal screw-pile light, located 1/3 of a mile off the northern tip of the Island, was commissioned early 1866. It exhibited a fixed white light through fifth order Fresnel lens. This second lighthouse lasted 15 years. In February of 1881 ice flows sheared the lighthouse from its piles and carried it for five miles down the Bay, with the keepers still inside.  In 1881 the Lighthouse Board urgently sought and received an appropriation of $35,000 for a replacement light. Due to the exposed location, a caisson light was decided upon and a contract for the ironwork was awarded to the Builders Iron Company of Providence, Rhode Island. Construction of the open-water work platform began while the caisson was assembled in Oxford, MD. On September 13th the caisson was floated to the light’s designated site and the job of sinking it into position began. There was a short delay between the construction of the caisson and that of the tower because the latter’s ironwork had not arrived. However, the construction was relatively uneventful. A fourth order Fresnel lens was exhibited on February 1, 1882 and the keepers moved in before the tower was fully completed. The construction crews were temporarily called away to work on other navigational aids, but returned in May and completed the tower.  Around 1940 the last remaining land of Sharps Island disappeared under the waters of the Bay.
  • In 1976 and ’77 scour and severe ice flows tilted the tower badly. The Fresnel lens was removed because of this and replaced with a plastic lens with a leveling apparatus. In 1982 the light was added to the National Register of Historic Places. The structure is currently in very poor condition.

Researched and written by Matthew B. Jenkins, a volunteer through the Chesapeake Chapter of the U.S. Light House Society.