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Divers salvage lighthouse history

The Coast Guard this summer teamed up with local archaeologists at Minot’s Ledge Lighthouse off Cohasset, Mass., to dive into history.

The Coast Guard this summer teamed up with local archaeologists at Minot’s Ledge Lighthouse off Cohasset, Mass., to dive into history.

Under the stone tower that stands today lies what Victor Mastone,

Read the other story in this package: A new life for our lighthouses

director and chief archaeologist of the Massachusetts Office of Coastal Zone Management, hopes to find: the remnants of the original lighthouse that stood there 156 years ago. “Our purpose of the dive[s] at Minot’s Ledge was to actually identify the remains of the 1850 lighthouse and develop data with long-term goals,” says Mastone. While the existing lighthouse has been on the National Register of Historic Places since 1987, Mastone would like to see the underwater remains commemorated as well.

Sitting about a mile off Cohassett, Minot’s Ledge Lighthouse marks a hazardous area known as Cohasset Rocks. The Boston Marine Society repeatedly petitioned Congress for a lighthouse between 1839 and 1841 after more than 40 vessels had been lost on the ledge, according to a history compiled by Jeremy D’Entremont, author of the “Lighthouse Treasury” series. In March 1847 Congress approved a $20,000 appropriation for a lighthouse and eventually set aside an extra $19,500 for completion.

Capt. William H. Swift was commissioned to build the lighthouse, and he approved an iron pile structure with legs drilled into the rock. His theory was that the structure would be more secure if waves passed through it rather than slamming against it. Congress supported the project because it would have been much more costly to build a stone tower on the shallow ledge. It was lighted for the first time Jan. 1, 1850. Shortly thereafter came reports from keepers that the structure was unsteady, swaying 2 feet in each direction during a storm.

The warnings should have been heeded. In April 1851 a storm ravaged coastal New England, and sometime during the three-day storm, the lighthouse tumbled into the sea. “It was a three- to four-day storm, and Boston became an island for a while,” says William Thiesen, the Coast Guard’s Atlantic Area Historian. “It was tragic because two of the lightkeepers [Joseph Wilson and Joseph Aintone] died going down with the structure.”

From 1851 to 1860 a lightship served as a replacement, and July 9, 1857, the first granite block was laid for the present tower, which was completed in 1860 and illuminated for the first time Nov. 15 of that year. It is still owned by the Coast Guard.

The Coast Guard divers were unable to locate any part of the original lighthouse on their first series of dives, from June 17 to 22. “They were able to get some experience, and we also honored the loss of the two lightkeepers, who were killed doing their duty, by placing an underwater memorial marker near the site,” says Thiesen. “It was a good learning experience, and everyone has been dedicated to the process.”

On Aug. 30 Mastone and Coast Guard teams from Massachusetts and New York met at the site to try their luck again and may have struck historical gold. “We found some pipe down in the area, and based on the descriptions of the joint structures we feel pretty confident it was part of the original metal structure of the old lighthouse,” says Mastone. “It was found on the last dive of the day.”

Mastone says the group was broken into two teams that each did 12 dives on the ledge. “They all had a good interest in artifacts, and their skills were very useful,” says Mastone. “We covered a lot of ground.”

When the dives were completed, Mastone was encouraged by the find. “We have to get it tested, but we’re really excited we finally found something,” he says. “The Coast Guard enjoys it because it is something different they [the divers] can participate in to hone their skills, and I get the byproduct of that.”