This article appears in the Fall 2026 issue
To mark the 250th anniversary of the Declaration of Independence, Estuary presents the second of two stories about the Connecticut River’s maritime contributions to the Revolutionary War. See also “The Connecticut River and the American Revolution,” Summer 2026.
Ezra Lee abandoning his attack on the HMS Eagle. From Cyril Field’s The Story of the Submarine from the Earliest Ages to the Present Day, 1908.
Like many great ideas, it started in a bar. In 1973 in a New Haven watering hole, Joe Leary’s brother introduced him to master boatbuilder Fred Frese. Joe was a submarine researcher who had the crazy idea (according to Fred) of creating a replica of David Bushnell’s Revolutionary War-era submarine, Turtle. Joe had come across Bushnell’s 1787 letter to Thomas Jefferson describing the underwater machine and was intrigued. Despite his skepticism, Fred agreed to help. They would learn that constructing a replica would be just as difficult as it was for Bushnell to build the original. It was literally history repeating itself.
Two hundred years earlier, Bushnell and his compatriots sat in their favorite tavern on the New Haven Green. Their heads together, they whispered about Bushnell’s latest invention, a mine that could function underwater to blow up British navy ships. That in itself was truly remarkable, but Bushnell’s dilemma was how to deploy such a weapon. He wanted to build a vessel that could submerge, sneak underwater to attach his mine to a ship, slip away without being seen, and await the great explosion and sinking of the ship from a safe distance.
David Bushnell (1740–1826) was born in Saybrook, Connecticut, in what is now the town of Westbrook. After his father died and his mother remarried, he sold his part of the family farm to his brother Ezra in order to attend Yale College in New Haven at the age of 31.
Yale’s extensive library provided Bushnell with information that led to his idea of building an underwater machine. It was also in New Haven where he garnered many supporters and materials for creation of the Turtle, so called because it looked like two shells put together.
Bushnell faced many engineering challenges, including buoyancy, propulsion, pumping, ventilation, navigation in the dark, and deployment of the mine. Everything about the Turtle required new mechanisms he had to invent. But the biggest challenge would be secrecy. If the British learned of his activities, he and his comrades would likely be executed for treason, like his Yale friend Nathan Hale.
Some of the most critical technical issues were buoyancy and propulsion, that is, the ability of the machine to submerge, rise, and move through the water. The shape that gave the Turtle its name was chosen to facilitate motion. Stabilizing the vessel required knowledge of tidal currents and density of the water: saltwater is heavier than freshwater and changes buoyancy. Bushnell needed 900 pounds of lead for ballast, but most lead was diverted for musket balls. One of his comrades, Isaac Doolittle, procured many of the essential resources.
Illustration of the Turtle’s interior as conceived by artist Mike Eagle. Photo: Connecticut River Museum.
Bushnell devised an early version of a propeller, described as an oar that looked like two arms of a windmill. One in the front moved the Turtle back and forth while another attached to the top moved it up and down. Everything was precisely milled and sealed tightly to prevent leakage.
Entry into the Turtle was through the top where the head of the two oak shells met. A round metal hatch that Bushnell called a crown or hat was hinged to the outside and sealed with screws. Once inside, the pilot sat with his head inside the crown where he could see out tiny windows; three could be opened for ventilation when above the surface. These and several others helped determine position if there was sufficient light, but operation would mostly be under the cover of darkness.
In order to function in the pitch dark, Bushnell devised a way to light instruments with “foxfire,” a bioluminescent fungus that grows on wood. He coated the compass needles and the cork bobber in his depth gauge or barometer with it. Unfortunately, foxfire is only available in warm weather and Bushnell had to cancel attacks planned for Boston in the winter of 1775–1776.
The last detail was the bomb itself. A screw on the top of the Turtle would be pushed up and screwed into the hull of the target vessel, released with the mine attached to a rope, and left behind as the pilot powered the Turtle away. Bushnell created a timer on the mine from clockworks that could be set at various intervals. When the timer went off, a firelock devise like that on a musket set off the mine containing 200 pounds of gunpowder.
Bushnell’s brother Ezra was most likely the first pilot. The pilot needed to be agile, strong, and have lots of stamina. He’d need to use his four limbs at the same time to operate the ballast intake, the rudder, and the two propellers. The pilot had about 45 minutes of air once submerged. To maintain secrecy, final adjustments and testing were done from the secluded Sill Farm near the Connecticut River at Ayers Point in Saybrook.
While it was a time of great intrigue, Bushnell was not working in a vacuum. By the time of the Turtle’s launch in Manhattan, it had been visited by Benjamin Franklin (October 1775) in Saybrook, and George Washington acknowledged it as “an effort of genius.” It was the hope for shortening the war.
Joe Leary (left) and Fred Frese building their replica of David Bushnell’s Revolutionary War-era submarine, 1976. Photo: Fred Frese.
During preparations for deployment, the pilot became ill, and Ezra Lee from Lyme, Connecticut, volunteered as replacement. The Turtle was ferried to New York, perhaps by the galley, Crane, built in East Haddam. It was deployed in New York harbor on the night of September 6, 1776. The target was the British navy’s flagship, the HMS Eagle. Unfortunately, the timing was off, and the tiny submarine and the novice Lee were set adrift during the wrong tidal change and into a difficult current.
Lee fought with all his strength to reach the ship. By the time he got close enough, it was almost daylight, and he was exhausted. Unable to secure the bomb to the ship’s hull, Lee set it free to find some other target while he tried to escape notice. The mine exploded but did not do damage. It did frighten the British navy into moving the fleet farther from shore. The age of the submarine was set in motion.
By the 20th century, Connecticut was about to become the submarine capital of the world, but Fred and Joe still faced a daunting task. Bushnell didn’t leave building specs for future admirers. His 1787 letter to Thomas Jefferson described his wondrous creation but with few details to direct anyone interested in replicating the Turtle. However, like Bushnell, Fred and Joe found supporters who helped guide their efforts and perform construction in Fred’s garage in rural East Haddam.
Although Bushnell tested his version in the Connecticut River, Fred and Joe opted for the swimming pool at Wolf’s Den Campground in East Haddam where they would have more control and better visibility before trying it out in the tidal river. While Bushnell had no celebratory debut, Turtle II was christened by Connecticut’s governor Ella Grasso at a public launching at the Connecticut River Museum in 1977, where it found a permanent home. Joe piloted the vessel, successfully submerging and maneuvering under a boat in Essex harbor.
Connecticut Governor Ella Grasso christening the Turtle II, August 20, 1977. Photo: Connecticut River Museum.
By the time I joined the staff of the museum as curator, the Turtle II had held pride of place for over 20 years, displayed in the middle of the main gallery. September 2001 marked the 225th anniversary of the Turtle’s first mission. The museum gave permission for Turtle II to go on display for a few days at Castle Clinton National Monument in New York City’s Battery Park.
I traveled with Turtle II to New York. It was quite a sight to see this oddity rolling down the highway on a flatbed truck. A huge crowd gathered on September 8 for the exhibition opening and speeches. Folks were fascinated by the unusual machine, what it did during the Revolution, and that it was actually launched nearby 225 years ago.
The Turtle was due to leave New York on Monday, September 10. The exhibition was so successful that Castle Clinton asked for the Turtle to stay another day. The museum declined, and it was safely back home on the morning of September 11, 2001! On reviewing the photos of the Turtle’s trip, there is one of the submarine parked on the street with one of the Twin Towers in the background.
Leary and Frese’s replica of the Turtle was on view at Castle Clinton National Monument in New York City’s Battery Park just days before the September 11, 2001, terrorist attack brought down the World Trade Center, shown in the background here. Photo: Alison C. Guinness.
Alison C. Guinness is a resident of East Haddam where she researches the local earthquake phenomenon called the Moodus Noises (See “Moodus Noises,” Summer 2024). She is an historian and naturalist with interest in Portland brownstone and other quarrying in the Connecticut River Valley.