The cold, dark depths of Seneca Lake are revealing a rare glimpse of the state’s early maritime history to a high-tech research vessel as it finds long-lost shipwrecks in the deepest of the Finger Lakes.

Armed with a multibeam sonar array, researchers from Middlebury College and the Lake Champlain Maritime Museum are producing accurate three-dimensional images of the bottom that also pinpoint wrecks from Seneca’s heyday of commercial canal shipping nearly two centuries ago.

Starting in late June, the Research Vessel David Folger was based in the newly-rebuilt marina at Sampson State Park for a two-week survey, headed by Thomas Manley, an assistant geology professor at Middlebury College, and Art Cohn, co-founder and director emeritus of the Lake Champlain Maritime Museum.

Called bathymetric mapping, the team’s work is providing valuable insights into an era when canals drove the state’s economy. The mission is being supported through a $15,000 grant from NYS Parks Historic Preservation Office and also by the NYS Canal Corp.

“On our first day on Seneca Lake, we found several shipwrecks,” said Cohn, pointing at a color-coded computer display that showed the crisp outline of one such vessel on the bottom. After a sighting, researchers sent down an unmanned, remote-operated vessel (ROV) to video, identify and document the scene.

“The vessels being found are intact ships, many with cargo, that have not been seen for more than 150 years,” he said.

Multibeam sonar works by sending sound waves in a fan shape into the water beneath a ship’s hull. The amount of time it takes sound waves to bounce off the bottom and return to a shipboard receiver is used to determine depth, with that data then used to produce detailed, color-coded maps.

These findings add to the eight shipwrecks located during a preliminary survey by the team in summer of 2018. So far, that brings the total number of confirmed shipwrecks to 14, with more potential finds still being analyzed, said Cohn.

The David Folger mapping project also will update lake navigation maps that date to the 1870s, when depth measurements were taken from ships by crews who dropped a lead weight from a metal chain into the lake until it hit bottom.

The newly-discovered Seneca Lake wrecks are canal boats that date from the mid-1820s to the 1850s, after the opening of the Erie Canal and construction the 20-mile Cayuga-Seneca Canal in helped make the lake part of the “superhighway” of the era.

The Erie (1825), Chemung (1833) and Crooked Lake (1833) canals helped make the lake commercially accessible from north, south and west, with hundreds of canal boats each year plying the 38-mile lake carrying cargoes of corn, coal, lumber, whiskey and other goods. But winds and storms on Seneca Lake posed a threat to such lake traffic, sometimes sending canal vessels to the bottom.

Seneca Lake is up to 625 feet deep, and water temperature at such depths is in the mid- to low-30s, said Cohn, making it the perfect low-oxygen environment for preserving wooden shipwrecks. In the ocean, salt water and aquatic organisms quickly corrode such wrecks

“The shipwrecks in Seneca Lake are in many way time capsules of the 19th century,” said Mark Peckham, a former maritime history expert with State Parks and now a trustee with the Hudson River Maritime Museum in Kingston.  “I dove on some wrecks in the 1990s and was struck by their state of preservation.  Some still had glass in their cabin windows and household items remaining inside.”

“These discoveries are especially significant as we are in the midst of the 200th anniversary of the construction of the NYS canal system.  2025 will mark the anniversary of the opening of the Erie Canal,” said Peckham. “More than anything else, the canals of the 1820s spurred economic development, settled broad swaths of the state, made New York State first in population and made the port of New York one of the greatest shipping ports in the world.  

The David Folger reached the lake from its home port on Lake Champlain by taking the Champlain, Erie and Cayuga-Seneca canals in the New York State Canal System.

The multibeam sonar array aboard the David Folger also allows researchers to understand the composition of the ground beneath the bottom of Seneca Lake, said Manley. Those sub-bottom images look almost like a slice through a layer cake.

Some images might offer clues into a long-running lake mystery _ the source of mysterious booming noises that seemingly come from the water itself. The sounds have been known locally as Seneca Guns, Lake Drums or Lake Guns.

One modern theory is that such sounds might be caused by the sudden collapse and depressurization of caverns or tunnels underneath the lake, which has a history of salt mining being done around and beneath it.

Manley pointed to a lake bottom image that shows such potential collapses _ a nearly-circular depression that is some 40 feet deep, and another such depression nearby that is shaped like a horseshoe.

As Seneca Lake shipwrecks are located, they will be protected as public resources under the Federal Abandoned Shipwreck Act of 1987. All shipwrecks located under this survey’s permit issued by the New York State Museum will be reported to the Museum and integrated into the state’s archaeological inventory.

Said Peckham, “These sites are subject to environmental degradation, such as silt deposit, erosion, organic deterioration, and the effects of mussel encrustation, and human intrusions like anchoring, diver handling, theft of artifacts, and construction of bulkheads, marinas, pipelines, and cable crossings. The latter threats can be addressed through improved public education and interpretation, law enforcement and by providing appropriate submerged heritage diving sites that foster and support responsible recreation and tourism.”

In Lake Erie, recreational diving on such historic wrecks has proved to be a popular tourist attraction. That could make Sampson State Park’ s rebuilt $7.5 million marina the perfect jumping-off point for such trips.

But not all mysteries have been uncovered yet _ researchers aboard the David Folger spotted no trace of potential relatives of a mythical Seneca Lake sea monster that was supposedly deliberately run over by the captain of a steamboat in 1899, according to a Rochester newspaper account at the time… But stay tuned.

Posted by Brian Nearing, NYS Parks deputy public information officer