Rhode Island Lighthouses




Block Island Southeast Lighthouse
(Block Island Lighthouse )


Block Island Southeast Lighthouse



Location: Mohegan Bluffs on the Southern Tip of Block Island
Location: 1875 - 1993 l Lat 41 09 09 N - Long 71 33 09 W
Location: 1875 - present l Lat 41 09 10.37 N - Long 71 33 04.196 W
Established: 1875

Lighthouse Constructed: 1875
Automated: 1990
Deactivated: 1990 - 1994
Original Illuminating Apparatus: First Order Fresnel Lens
Current Illuminating Apparatus: First Order Fresnel Lens
Height: 67 feet
Status: Active Aid to Navigation/Museum
Light Characteristic: Lighthouse: Fixed White (1906)

Light Characteristic: Lighthouse: Flashing Green every 3.7 seconds (1932)

Light Characteristic: Lighthouse: FlashingGreen every 5 seconds (2019)

Light Characteristic: Skeleton tower: Flashing Green every 5 seconds (1990 - 1994)
Range: Lighthouse: 21 miles (1906)
Range: Lighthouse: 20 miles (2005)

Range: Skeleton tower: 24 miles (1990 - 1994)
Fog Signal: 1st-class Steam Siren (1900)
Fog Signal: 1st-class Automatic Compressed Air Siren (1912)
Fog Signal Characteristic: Siren Blast for 4 Seconds (1912)
Fog Signal Characteristic: Silent for 30 Seconds
Fog Signal Characteristic: Siren Blast for 4 Seconds
Fog Signal Characteristic: Silent for 30 Seconds
Location: Established: Lighthouse Constructed: Automated: Deactivated: Original Illuminating Apparatus: Current Illuminating Apparatus: Height: Status: Light Characteristic: Range: Fog Signal: Fog Signal Characteristic:


The Block Island Southeast Lighthouse was built in 1874 on a ten acre plot of land on the southern tip of Block Island. The red brick lighthouse was equipped with a first order Fresnel lens made expressly for it by Barbier and Fenestre of Paris.

Block Island Southeast lighthouse first fog signal, two sets of steam sirens, were housed in a wood frame building, 15 feet by 30 feet. It burned down on April 28,1908. A larger brick building was constructed shortly after the fire to house the fog signal. This fog signal was used until 1974, when it replaced by an electric fog signal.

In 1929 the Block Island Southeast Lighthouse was changed from a fixed white light to a flashing green. The light's original lens was moved to another location. A new first Fresnel order lens and a revolving apparatus was placed in the light. The new lens, a combination of other lenses consisted of just eight lens panels. They revolved on a bed of mercury that allowed vibration free rotation of the lens.

In 1990, for safety and environmental reasons, the Coast Guard removed the mercury and closed the light. It was replaced by light on a skeleton tower.

When Block Island Southeast Lighthouse was built in 1874, three hundred feet of land lay between it and edge of Mohegan Bluffs and the ocean. Over the next hundred years the bluff eroded to within seventy-five feet of the light. If something wasn't done soon, the light would light fall into the ocean.




In 1983 the Block Island Southeast Lighthouse Foundation was formed to save the light. The only way to do this was move it. It took the Foundation nearly ten years to raise the $2,000,000 to move the light. Half the money came from a federal grant. The rest came from selling some of the land to state and private sources.

On August 13, 1993, the lighthouse started its move inland. It took nineteen days to move it to a new location, three hundred feet from the bluff. It had to be moved in a zigzag pattern, so no one part of the light would receive too much stress.

After the move, the Block Island Southeast Lighthouse Foundation wanted to relight the lighthouse. The first order Fresnel lens at the light couldn't be used because the mercury had been removed from the revolving apparatus. The Coast Guard removed the lens and replaced it with another first order lens from the Cape Lookout Lighthouse in Beaufort, North Carolina. The Block Island Southeast Light was relighted on August 27, 1994. The Foundation has a small museum at the light.

Panoramic of Block Island Southeast Lighthouse


For more detail information on Block Island Southeast Lighthouse read Historic American Engineering Record No. RI-27.

See more of Block Island Southeast Lighthouse in Rhode Island Lighthouses: A Pictorial History by R Holmes.


For information on the Block Southeast Lighthouse Foundation, contact:


Block Island Southeast Lighthouse Foundation
Box 949
Block Island, RI 02807
Updated 9/8/2019