Local history buffs will have the opportunity to learn more about unique structures that dotted the Chesapeake Bay and Maryland waters during a presentation on Saturday at the Isle of Wight County Museum in Smithfield.

The program will explore “Screwpiles: The Forgotten Lighthouses,” a pictorial history book from the Suffolk River Heritage Foundation published earlier this year. Suffolk River Heritage chairman Karla Smith and Larry Saint will conduct the presentation with a focus on how these lighthouses relate to history along the James River and other local waterways.

“I think it’s of high interest to the people in Smithfield,” Smith said in a phone interview.

The screwpile lighthouses were built in southeastern Virginia, northeastern North Carolina and southern Maryland in the 19th century before the Civil War. According to marinersmuseum.org, there were 42 screwpile lighthouses built on the Chesapeake Bay between 1850 and 1900, more than anywhere else in the world, and based on an English design.

Seven iron legs were screwed into the bottom of the bay in a hexagonal pattern. Cottages were built on top of the iron foundation for the keepers, with lights placed at the very top of the structures. Most screwpile houses were torn down in the 1960s, but many of the iron bases of the structures are still used for automated lights and fog signals.

Smith and Saint worked with fellow Suffolk River Heritage members Phyllis Speidell and John Sheally II, who interviewed descendants of former lighthouse keepers and their relatives, some of whom were found in Smithfield. Saint said the presentation will be tailored specifically for a Smithfield audience.

“I’m going to go into a little bit more depth on their specifications, how they were built and how long it took to build them,” he said, along with how the role they played in the Civil War.

The free and public presentation will be held from 10 to 11 a.m. this Saturday at the museum located at 103 Main St. in Smithfield. The presentation is expected to be about 30 minutes, followed by a question-and-answer segment. Signed copies of the book will also be available for purchase on site.

Visit historicisleofwight.com for more information.